Diet Pepsi's Refreshing Rewards Facebook campaign uses banner ads and a mobile-optimized website to inspire daily interaction among fans, writes Lauren Johnson. Though the Web page call-to-action is clear and the Facebook coordination avoids form-filling hassles, one consultant criticized the banner ad lead-in. "The design of the mobile banner ad works well, however there is not a clear call-to-action on the banner ad, simply a Go button -- with the logo and tagline," says Siteminis CEO Marci Troutman.