The site drew 8.03 million unique users in May--a 69 percent increase over the same month last year, according to Nielsen//NetRatings. (ABC says the shows, which include "Lost" and "Desperate Housewives," were viewed over 11 million times on the site in May.)

The network is in the midst of a two-month test to gauge consumer interest in viewing shows online, although it says it is leaning toward continuing to do so in the fall.

Although ABC.com appears to have benefited from the experiment--which has 10 advertisers on board as sponsors--the site still lags behind NBC.com in terms of growth in unique users, perhaps because of the NBC site's "Deal or No Deal" content. NBC.com saw unique users grow by 117 percent in May over last year (to 7.95 million--almost on par with ABC), according to Nielsen//NetRatings.

The Fox Web site drew the most unique users of the Big 4 networks' sites, although that may be slightly deceiving, since the figures include traffic to AmericanIdol.com. Fox had 8.51 million unique users in May--a 66 percent increase over last year, according to Nielsen//NetRatings.

The Web sites for ABC, NBC, and Fox all posted huge growth versus a year ago, in step with the general rise in Internet usage and attraction to online video. Somewhat surprisingly--particularly since it launched broadband channel "innertube" on May 4--the CBS site showed a slight drop in unique users, according to Nielsen//NetRatings. The site saw unique users decline by 2 percent in May versus a year ago, to 5.35 million.

In early May, ABC reached an agreement with several of its affiliate groups to allow one of their stations' local Web sites to link to the streamed episodes on ABC.com. Due to a failure to meet minimum sample size, only one of those stations' sites registered in Nielsen//NetRatings figures. But Belo Corp.'s Dallas-based WFAA.com saw an 88 percent jump in unique users in May compared to last year (to 747,000), according to Nielsen//NetRatings.

Unlike Fox, ABC does not have a deal with affiliates to share revenue from the online repurposing of content--something that has frustrated affiliates. But the network maintains that online distribution leads to more viewers on-air, and stations in turn benefit from higher ratings.

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