Web Site Traffic Metrics

Below are the original proposed definitions from my site optimization research conducted from 1998 to 2000. These ideas ended up bundled into the Marketers Common Sense Guide to eMetrics, download PDF here. If you're looking for customer analysis, check out the Drilling Down book sample here.

Take Rates on Key Action Items
(now referred to as Conversion Rate)
Percent of Unique Visitors engaging in the activity desired.  This is a measure of how compelling your offerings are to the audience you get at the site, and how well you are marketing to them.  

The accuracy of the absolute Take Rate number depends on how accurate your Unique Visitors are as explained above.  Accuracy is not your prime concern.  What really matters is the relative measurement - does this percentage go up or down over time?  As you test different locations in the site, link titles, subscription methods, traffic generating ideas, advertising copy and placement, paid search links, PPC ads, and so forth, can you continuously keep the Take Rate rising?

Repeat Visitor Share
Percent  Unique Visitors coming back over time.  This can vary dramatically based on the Session Length variable and the period of time you are running you report for.  Most sites want their visitors to come back, so the Repeat Rate is something you want to see rise over time.  If it doesn't, you are not improving the quality of your content / products or the ability to attract visitors who actually like your content / products.  

Once you pick at Session Length variable and time frame to run your report over (a day, a week, a month) don't change them or you lose the track-ability of this metric.

Committed Visitor Share  
Percent of very long visits, similar in nature to Heavy User Penetration above, only using time-based visits instead of Page Views.  If you want visitors to stick around for a long time, you want to see this metric move higher.  If you want them to be able to do their business efficiently and move on, you want this metric moving lower over time.  Virtually all catalog-type B2C commerce sites would want this metric moving down over time.   Community, Game, and Auction sites probably want it moving up over time.  Are you attracting the right kind of Visitors?

Committed Visitor Volume 
Percent of total Page Views on the site viewed by Visitors with very long visit behavior.  For an advertising-driven site, this is a metric bound to get attention, because it speaks to the overall quality of a page view.  If you have 100,000 page views and only 1% of them can be attributed to visitors who stick around for a while, in most cases you are attracting the wrong audience, and this audience is not really worth much.  Most sites would want to see this percentage rising over time.

Visitor Engagement Index 
This is Sessions divided by Unique Visitors, indicating the tendency for multiple sessions on the part of users.  Unlike "repeat visitors," this metric gives you a feel for the "intensity" of repeating behavior.  If you have a very targeted audience of the same people who come back over an over again, the index will be well over 1.  If you have no repeat visitors, it will be very close to 1, meaning almost every visitor has one session.  Whether you want this metric to trend up or down depends on the site.  Content sites probably want to see multiple sessions per visitor, and want this number to pop higher; commerce sites might want it as close to 1 as possible. 

Note: if you suspect users interact with your site over multiple sessions in a relatively short amount of time (1 hour) to accomplish one task (e.g. shopping from work), and you know you are getting pretty accurate Unique Visitor counts using cookies, you might want to play around with the Session Length variable to more closely capture the actual behavior of a customer.  As you increase Session Length, this index falls towards 1. 

Reject Rate: All Pages
(now referred to as Bounce Rate)
Percent Visitors who Viewed any page once and then left, this metric frequently ties to broad navigation or design issues.  While focusing on top entry pages is more important in the short term because that is where the traffic is happening, this more global metric is likely to point to global design flaws in navigation or page layout.  When you make global design changes, pay attention to this one - you want it to be forever falling. 

Scanning Visitor Index 
Pages scanned in a one minute or less visit.  The closer this index is to 1 page, the less useful people are finding your site - they're just reading one page and leaving.  This could signal navigation problems (or poor targets from marketing).  If you make significant navigation or design changes, look to this index to rise.  If it falls, you have hurt your usability and should look for ways to improve it. 

If you want to learn how to use these metrics and others to improve the profitability of a web site, you can get started by downloading the Visitor Quality / Engagement Calculator for WebTrends at the link below.  

If you're in a hurry and want the whole story wrapped up in a package, get the 76 page Guide to Web Analytics right here.