1. "Absolute unique visitors" are defined by Google Analytics as (as of Nov. 4, 2009): "[also called unique visitors] Unique Visitors represents the number of unduplicated (counted only once) visitors to your website over the course of a specified time period. A Unique Visitor is determined using cookies." ProCon.org determines absolute unique visitors each month then adds all the monthly data together for the year's total.

2. "Pageviews" are defined by Google Analytics as (as of Nov. 4, 2009): "A pageview is defined as a view of a page on your site that is being tracked by the Analytics tracking code. If a visitor hits reload after reaching the page, this will be counted as an additional pageview. If a user navigates to a different page and then returns to the original page, a second pageview will be recorded as well."

 

3. "Hits" are defined by Webopedia as (as of Nov. 4, 2009): "Also called a page hit. The retrieval of any item, like a page or a graphic, from a Web server. For example, when a visitor calls up a Web page with four graphics, that's five hits, one for the page and four for the graphics. For this reason, hits often aren't a good indication of Web traffic." [Note: A definition of "hit” was not found on Google Analytics or Urchin.]

 

4. "Ad impressions" are defined by Webopedia as (as of May 11, 2010): "An advertisement's appearance on an accessed Web page. For example, if the page you're on shows three ads, that's three impressions. Advertisers use impressions to measure the number of views their ads receive, and publishers often sell ad space according to impressions."

5. "Sessions" are defined by Urchin (now owned by Google) - the sofware program used to track our traffic website - as (as of Nov. 4, 2009) any 30-minute or less period of time in which an individual IP address accesses one or more files from one ProCon.org website.

Some examples of how sessions are counted:

* If a person looks at the Medical Marijuana ProCon.org Historical Timeline for five minutes, leaves their computer for 15 minutes to get a snack, and then returns to view the Medical Marijuana ProCon.org Votes and Polls page, then that use counts as one session.

* If a person looks at ProCon.org for five minutes, then ACLU ProCon.org for 10 minutes, then back to ProCon.org for five minutes, then that use counts as two sessions.

* If a person looks at US-Iraq ProCon.org for 10 minutes, then Israeli-Palestinian ProCon.org for 40 minutes, and then back to US-Iraq ProCon.org for 30 minutes, then that use counts as four sessions.

* If a person uses ACLU ProCon.org for 70 minutes, then uses Born Gay ProCon.org for 70 minutes, then that use counts as six sessions.

* If a person uses each six of ProCon.org's websites for 40 minutes each, then that use counts as 12 sessions.

* If a person looks at a ProCon.org issue site (Born Gay ProCon.org, ACLU ProCon.org, etc.) for 20 minutes, then an hour later revisits the same site for another 5 minutes, then that use counts as two sessions.

Note, however, that we have learned as of Aug. 2008 that:

A. If a person looks at a third party website (say, for example, Google.com) for two seconds and that Google.com page happens to have on it an image (say, for example, a button labeled "Visit ProCon.org") loading directly from the ProCon.org website, then the ProCon.org button having loaded on the Google.com page counts as one session even though the person never clicked on the "Visit ProCon.org" button and may not have even noticed the button. However, if that same "Visit ProCon.org" button loaded directly from the Google.com website vs. directly from the ProCon.org website, then it would not count as a session.

[Note: We did not count 90,000 sessions for Medical Marijuana ProCon.org in July 2008 because the traffic came from a button at stopthedrugwar.org using an image that loaded directly from the ProCon.org server. We also did not count 64,722 sessions in the third quarter of 2008 because that traffic came from an image on the 2008 Election ProCon.org website that was being loaded directly from our Under God ProCon.org website. The reason that we removed the 154,722 "sessions" was because those visitors had not even viewed the site that recorded the session.]

B. Because we changed our URLs on June 30, 2008 to include third-level domains (aclu.procon.org, medicalmarijuana.procon.org, borngay.procon.org, etc) instead of their prior two-level domain format (www.acluprocon.org, www.medicalmarijuanaprocon.org, www.borngayprocon.org, etc.) if a person visits a bookmarked ProCon.org URL (say www.medicalmarijuana.procon.org/california.htm) that automatically redirects him/her to a different URL on a new third-level domain ProCon.org website (say medicalmarijuana.procon.org/california.asp) then that counts as two sessions even though the person never consciously selected two sites to visit.

[Note: We did not count 216,574 sessions in the third quarter of 2008 because that traffic was coming from WWW links that were being automatically routed to non-WWW pages and were therefore being double counted.]

6. Extrapolations. While ProCon.org traffic software has always tracked sessions, it has not always tracked absolute unique visitors, pageviews, and hits. Some of the traffic data (absolute unique visitors, 2004-2007; pageviews and hits, 2004-2005) were extrapolated based on their relation to sessions traffic.