Twitter execs said their main motivation for doing a redesign of Twitter.com, which they unveiled Tuesday, was to make it “faster, easier, richer, more efficient to use,” as Biz Stone put it. Monetization was so low on the list of design objectives that execs said they hadn’t even shown the new site to advertisers before yesterday’s launch. But, in an interview, Stone said he thinks the new design does offer the possibility for “new revenue-generating opportunities.” AllThingsD: Twitter’s new website has lots of cool features and gizmos. But they’re all supposed to do one thing in particular: Encourage you to spend more time on Twitter.com, where the company can show you some ads. The Twitter folks don’t exactly present it that way, of course.