For e-retailers planning Mother’s Day campaign strategies, a recent study by web analytics company Compete Inc. that tracked the performance of Valentine’s Day banner ads on Yahoo, MSN.com and AOL.com offers some insights.

The study of the performance of all-day banner ads from 1-800-flowers.com and Proflowers.com, which ran on intermittent dates on the home pages of all three portals between Feb. 9-13, found that consumers who saw the ads on Yahoo’s home page were twice as likely to make a same-day purchase from the online florist sites than a control group that visited the portal during the same period on days when the banner ads didn’t run.

By contrast, those viewing the banner ads on portal MSN during the test period were 1.6 times as likely to make a same-day purchase as the control group, while those viewing the banner ad on AOL were 1.2 times as likely.

The rate of lift in visits to a site told a different story. Consumers who viewed the all-day banners on MSN.com were 1.73 times more likely to visit the florist sites on the same day they saw the ad-whether through an immediate direct click-through or a later visit-during the test period than the control group was. Those seeing the ads on AOL were 1.69 times more likely to visit, and those seeing the ads on Yahoo were 1.61 times more likely to visit the sites.

Alex Patriquin, Compete strategist, says the study may help retailers who are promoting similar products this Mother’s Day make choices about where to advertise.

Compete tracks consumer behavior on the web through a panel of 2 million users.