Pageview times experiment (#69)

* experiment: track pageview times

* strictly respect do not track

* oops

* asdfasdfasdf

* add blogpost

* fix typos oops

blog/pageview-time-experiment-2019-08-19.markdown

@@ -0,0 +1,72 @@
+---
+title: Pageview Time Experiment
+date: 2019-08-19
+---
+
+# Pageview Time Experiment
+
+My blog has a lot of content in a lot of diverse categories. In order to help me
+decide which kind of content I should publish next, I have created a very
+simple method to track pageview time and enabled it for all of my blogposts. I'll
+go into detail of how it works and potential risks of it below.
+
+The high level idea is that I want to be able to know what kind of content has
+people's attention for the longest amount of time. I am using the time people
+have the page open as a particularly terrible proxy for that value. I wanted to
+make this data anonymous, simplistic and (reasonably) public.
+
+## How It Works
+
+Here is how it works:
+
+<center>![A diagram on how this works](/static/img/pageview_flowchart.png)</center>
+
+When the page is loaded, a [javascript file records the start time](/static/js/pageview_timer.js).
+This then sets a [pagehide handler](https://developer.mozilla.org/en-US/docs/Web/API/Window/pagehide_event)
+to send a [navigator beacon](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/sendBeacon)
+containing the following data:
+
+- The path of the page being viewed
+- The start time
+- The end time recorded by the pagehide handler
+
+This information is asynchronously pushed to [`/api/pageview-timer`](https://github.com/Xe/site/blob/91d7214b341088edba7a37a83a753e75ed02d7ad/cmd/site/pageview.go)
+and added to an in-memory prometheus histogram. These histograms can be checked at 
+[`/metrics`](/metrics). This data is not permanently logged.
+
+## Security Concerns
+
+I believe this data is anonymous, simplistic and public for the following reasons:
+
+I believe this data is anonymous because there is no way for me to correlate users
+to histogram entries, nor is there a way for me to view all of the raw histogram
+entries. This site records the bare minimum for what I need in order to make sure
+everything is functioning normally, and all data is stored in ephemeral in-memory
+containers as much as possible. This includes any logs that my service produces.
+
+I believe this data is simplistic because it only has a start time, a stop time
+and the path that is being looked at. This data doesn't take into account things
+like people leaving a page open for hours on end idly, and that could skew the
+numbers. The API endpoint is also fairly unprotected, meaning that falsified data
+could be submitted to it easily. I think that this is okay though.
+
+I believe this data is public because I have the percentile views of the histograms
+present on [`/metrics`](/metrics). I have no reason to hide this data, and I do not
+intend to use it for any moneymaking purposes (though I doubt it could be to begin
+with).
+
+I fully respect the [do not track](https://allaboutdnt.com) header and flag in browsers.
+If [`pageview_timer.js`](/static/js/pageview_timer.js) detects the presence of
+do not track in the browser, it stops running immediately and does not set the pagehide
+handler. If that somehow fails, the server looks for the presence of the `DNT` header
+set to `1` and instantly discards the data and replies with a 404.
+
+Like always, if you have any questions or concerns please reach out to me. I
+want to ensure that I am creating useful views into how people use my blog
+without violating people's rights to privacy.
+
+I intend to keep this up for at least a few weeks. If it doesn't have any practical
+benefit in that timespan, I will disable this and post a follow-up explaining how
+I believe it wasn't useful.
+
+Thanks and be well.

cmd/site/main.go

@@ -223,6 +223,7 @@ func Build() (*Site, error) {
 		w.Header().Set("Content-Type", "application/xml")
 		_, _ = smi.WriteTo(w)
 	})))
+	s.mux.HandleFunc("/api/pageview-timer", handlePageViewTimer)
 
 	return s, nil
 }

cmd/site/pageview.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"within.website/ln"
+)
+
+var (
+	readTimes = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Name: "blogpage_read_times",
+		Help: "This tracks how much time people spend reading articles on my blog",
+	}, []string{"path"})
+)
+
+func init() {
+	_ = prometheus.Register(readTimes)
+}
+
+func handlePageViewTimer(w http.ResponseWriter, r *http.Request) {
+	if r.Header.Get("DNT") == "1" {
+		http.NotFound(w, r)
+		return
+	}
+
+	data, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		ln.Error(r.Context(), err, ln.Info("while reading data"))
+		http.Error(w, "oopsie whoopsie uwu", http.StatusInternalServerError)
+		return
+	}
+	r.Body.Close()
+
+	type metricsData struct {
+		Path      string    `json:"path"`
+		StartTime time.Time `json:"start_time"`
+		EndTime   time.Time `json:"end_time"`
+	}
+	var md metricsData
+	err = json.Unmarshal(data, &md)
+	if err != nil {
+		http.NotFound(w, r)
+		return
+	}
+
+	diff := md.EndTime.Sub(md.StartTime).Seconds()
+
+	readTimes.WithLabelValues(md.Path).Observe(float64(diff))
+}

go.mod

@@ -6,9 +6,7 @@ require (
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/pkg/errors v0.8.1 // indirect
 	github.com/povilasv/prommod v0.0.12
-	github.com/prometheus/client_golang v0.9.4
+	github.com/prometheus/client_golang v1.0.0
-	github.com/prometheus/common v0.4.1 // indirect
-	github.com/prometheus/procfs v0.0.0-20190523193104-a7aeb8df3389 // indirect
 	github.com/russross/blackfriday v2.0.0+incompatible
 	github.com/sebest/xff v0.0.0-20160910043805-6c115e0ffa35
 	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect

go.sum

@@ -1,4 +1,3 @@
-github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
@@ -8,14 +7,11 @@ github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/celrenheit/sandflake v0.0.0-20190410195419-50a943690bc2 h1:/BpnZPo/sk1vPlt62dLya5KCn7PN9ZBDrpTGlQzgUZI=
 github.com/celrenheit/sandflake v0.0.0-20190410195419-50a943690bc2/go.mod h1:7L8gY0+4GYeBc9TvqVuDUq7tXuM6Sj7llnt7HkVwWlQ=
-github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
-github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
@@ -37,40 +33,24 @@ github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
-github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/povilasv/prommod v0.0.11 h1:uiCU9z2UpNoMFyd5h3evJB8mTBuT9lZU3CYpMZkkyE0=
-github.com/povilasv/prommod v0.0.11/go.mod h1:kMc6cpm22gp7m0cPEFRoRgIzXq75ZIJvNY6GbNu9EJk=
 github.com/povilasv/prommod v0.0.12 h1:0bk9QJ7kD6SmSsk9MeHhz5Qe6OpQl11Fvo7cvvmNUQM=
 github.com/povilasv/prommod v0.0.12/go.mod h1:GnuK7wLoVBwZXj8bhbJNx/xFSldy7Q49A44RJKNM8XQ=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
-github.com/prometheus/client_golang v0.9.2/go.mod h1:OsXs2jCmiKlQ1lTBmv21f2mNfw4xf/QclQDMrYNZzcM=
-github.com/prometheus/client_golang v0.9.3 h1:9iH4JKXLzFbOAdtqv/a+j8aewx2Y8lAjAydhbaScPF8=
-github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
-github.com/prometheus/client_golang v0.9.4 h1:Y8E/JaaPbmFSW2V81Ab/d8yZFYQQGbni1b1jPcG9Y6A=
-github.com/prometheus/client_golang v0.9.4/go.mod h1:oCXIBxdI62A4cR6aTRJCgetEjecSIYzOEaeAn4iYEpM=
 github.com/prometheus/client_golang v1.0.0 h1:vrDKnkGzuGvhNAL56c7DBz29ZL+KxnoR0x7enabFceM=
 github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5FsnadC4Ky3P0J6CfImo=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 h1:S/YWwWx/RA8rT8tKFRuGUZhuA90OyIBpPCXkcbwU8DE=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
-github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
-github.com/prometheus/common v0.0.0-20181126121408-4724e9255275/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
-github.com/prometheus/common v0.4.0/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/common v0.4.1 h1:K0MGApIoQvMw27RTdJkPbr3JZ7DNbtxQNyi5STVM6Kw=
 github.com/prometheus/common v0.4.1/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
-github.com/prometheus/procfs v0.0.0-20181204211112-1dc9a6cbc91a/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
-github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
-github.com/prometheus/procfs v0.0.0-20190523193104-a7aeb8df3389 h1:F/k2nob1S9M6v5Xkq7KjSTQirOYaYQord0jR4TwyVmY=
-github.com/prometheus/procfs v0.0.0-20190523193104-a7aeb8df3389/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.0.2 h1:6LJUbpNm42llc4HRCuvApCSWB/WfhuNo9K98Q9sNGfs=
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
-github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/russross/blackfriday v2.0.0+incompatible h1:cBXrhZNUf9C+La9/YpS+UHpUT8YD6Td9ZMSU9APFcsk=
 github.com/russross/blackfriday v2.0.0+incompatible/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
 github.com/sebest/xff v0.0.0-20160910043805-6c115e0ffa35 h1:eajwn6K3weW5cd1ZXLu2sJ4pvwlBiCWY4uDejOr73gM=
@@ -82,7 +62,6 @@ github.com/snabb/diagio v1.0.0 h1:kovhQ1rDXoEbmpf/T5N2sUp2iOdxEg+TcqzbYVHV2V0=
 github.com/snabb/diagio v1.0.0/go.mod h1:ZyGaWFhfBVqstGUw6laYetzeTwZ2xxVPqTALx1QQa1w=
 github.com/snabb/sitemap v1.0.0 h1:7vJeNPAaaj7fQSRS3WYuJHzUjdnhLdSLLpvVtnhbzC0=
 github.com/snabb/sitemap v1.0.0/go.mod h1:Id8uz1+WYdiNmSjEi4BIvL5UwNPYLsTHzRbjmDwNDzA=
-github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
@@ -92,14 +71,13 @@ golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnf
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20180811021610-c39426892332/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/net v0.0.0-20181201002055-351d144fa1fc/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190522155817-f3200d17e092 h1:4QSRKanuywn15aTZvI/mIDEgPQpswuFndXpOj3rKEco=
 golang.org/x/net v0.0.0-20190522155817-f3200d17e092/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a h1:1BGLXjeY4akVXGgbC9HugT3Jv3hCI0z56oJR5vAMgBU=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
@@ -109,9 +87,5 @@ gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-within.website/ln v0.5.2 h1:4pTM2wzpLjeZAputLf2U29HD79vcmdoEI/VPm2QEYgs=
-within.website/ln v0.5.2/go.mod h1:ifURKqsCJekcsdUE+hyCdcuhQqQ+9v9DfA++ZqYxZFE=
-within.website/ln v0.6.0 h1:zn8vE9f0biSTNIpHFc7kOPH+SitLsWrU1MfrwMSS4cM=
-within.website/ln v0.6.0/go.mod h1:ifURKqsCJekcsdUE+hyCdcuhQqQ+9v9DfA++ZqYxZFE=
 within.website/ln v0.7.0 h1:cZUc53cZF/+hWuEAv1VbqlYJ5czuPFHKfH0hLKmlIUA=
 within.website/ln v0.7.0/go.mod h1:ifURKqsCJekcsdUE+hyCdcuhQqQ+9v9DfA++ZqYxZFE=

scripts/docker.sh

@@ -3,4 +3,4 @@
 set -e
 
 docker build -t xena/site .
-exec docker run --rm -itp 5000:5000 -e PORT=5000 xena/site
+exec docker run --rm -itp 5030:5000 -e PORT=5000 xena/site

static/js/pageview_timer.js

@@ -0,0 +1,31 @@
+/*
+  Hi,
+
+  If you are reading this, you have found this script in the referenced scripts
+  for pages on this site. I know you're gonna have to take me at my word on this,
+  but I'm literally using this to collect how much time people spend reading my
+  webpages. See metrics here: https://christine.website/metrics
+
+  If you have the "do not track" setting enabled in your browser, this code will
+  be ineffectual.
+*/
+
+(function() {
+    let dnt = navigator.doNotTrack;
+    if (dnt === "1") {
+        return;
+    }
+
+    let startTime = new Date();
+
+    function logTime() {
+        let stopTime = new Date();
+        window.navigator.sendBeacon("/api/pageview-timer", JSON.stringify({
+            "path": window.location.pathname,
+            "start_time": startTime.toISOString(),
+            "end_time": stopTime.toISOString()
+        }));
+    }
+
+    window.addEventListener("pagehide", logTime, false);
+})();

templates/blogpost.html

@@ -18,6 +18,9 @@
 
 <link rel="canonical" href="https://christine.website/{{ .Link }}">
 
+<!-- Metrics -->
+<script src="/static/js/pageview_timer.js"></script>
+
 <script type="application/ld+json">
  {
    "@context": "http://schema.org",
@@ -69,10 +72,10 @@ function share_on_mastodon() {
                 if ( !instance.startsWith("https://") && !instance.startsWith("http://") )
                         instance = "https://" + instance;  
 
-                // Get the current page's URL
+                // get the current page's url
                 var url   = window.location.href;
         
-                // Get the page title from the og:title meta tag, if it exists.
+                // get the page title from the og:title meta tag, if it exists.
                 var title = document.querySelectorAll('meta[property="og:title"]')[0].getAttribute("content"); 
         
                 // Otherwise, use the <title> tag as the title