Long-time readers know that online testing is a constant theme of this publication. It's been said that "online marketing is testing" -- if you're not testing, you're not really marketing.

That's why one of our favorite marketing websites is whichtestwon.com. This site is from Anne Holland, whom you might know from her tenure at Marketing Sherpa.

The site is dedicated to educating marketers on the latest trends in the online world and about conversion optimization in particular. We especially enjoy the "Free Test of the Week." It's harder than it looks.

You can take the weekly quiz here. We don't get it right as often as we'd like. Give it a shot and good luck!