CTR:
Short for click-through
rate, the ratio of the number
of times a user clicks on an online
advertisement per number of viewers who
view the Web site that has the
advertisement on it. For example, if one
out of 100 people who visit a specific
Web site click on an advertisement and
are taken to the advertiser's site, then
the CTR of that advertisement is 1/100,
or 1%.
