comScore is adding a new metric, "visits" - which the measurement
firm defines as the number of distinct times people visit a site per
day, with at least 30 minutes between each visit - which could
potentially replace the pageview as a key advertiser metric, reports ClickZ (via MarketingVox).

Whereas pageviews generate a raw number of
how many pages on the site were hit in a given period, visits point to
a user's engagement with the site. Tracking visits, comScore says, will
give a picture of how many times the same person comes back, indicating
the level of loyalty toward the site.

Another driving force behind a new metric is that non-HTML
web-authoring technologies such as Flash and AJAX do not create pages
per se; therefore, pageviews don't, as a practical matter, exist and so
aren't recorded - even though a user may be interacting with the site.
Developers use these technologies because they build slicker and more
user-friendly sites.

One problem for advertisers is that visits, unlike pageviews, don't
correspond to ad impressions. But coupling visits with a site's reach
and the length of each stay offers a fuller picture of the site's
audience.

ON: Visits’ The New Measure of Web-User Engagement via @jpenabickley