Eric Ries once told me a story of something he screwed up. He told me he built a website, which took six months of his life, and no one ever visited it. Taught him a valuable lesson: test your ideas to see if anyone will care BEFORE you spend six months of building time (he’s famous in San Francisco tech circles for coming up with a methodology called “Lean Startup” and I was lucky enough to sit down with him to understand that. My video with Ries is here: Part I, Part II).

But how do you do that? Well, Eric’s idea was to measure how many of his friends would actually visit a prototype website before building it out. If none of his friends were interested, then he’d refactor until he could get some of his friends interested enough in the idea to click over.

Today Zurb has a better idea. They built a testing tool, called Verify, that lets you upload pictures of websites, or even wireframes or roughly-sketched out site ideas. Then you can ask your Twitter or Facebook followers, or even your friends, what they think or, even better, whether they are finding what the purpose of the website is.

The end result is a heatmap of where people clicked and how long it took them to figure it out.

Zurb’s founders, for instance, did one test while we watched. They knew that Rackspace was famous for having fanatical support. So, they took a capture of Rackspace’s website and posted that on Verify while asking their users “tell us where you’ll go for support on Rackspace’s home page.”

The resulting heatmap shows where people clicked. Hotter areas show where people clicked the fastest.

This is invaluable for helping increase conversion ratios. You can test lots of versions to see if putting the “buy” button, for instance, on top left, increases conversion over putting it at bottom right.

I sat down with Bryan Zmijewski, founder and Chief Instigator of ZURB, and Jonathan Smiley, a designer at ZURB, to find out more about their ideas in a 20 minute interview that’s well worth your time to watch.

Oh, why is Zurb qualified to build such a tool? They do user interaction design for all sorts of companies from eBay to Facebook. They use this tool to help them convince their clients that their designs have value and are the correct way to go.

You don’t need to just test website designs, either, in Verify. You can test logos. Imagine if the Gap did that before trying to roll out an ugly new logo! Anyway, if you aren’t using tools like Verify to really find out if your website is working you’re missing out on one of the best new marketing tools around.

A shorter version of this video is over on Building43.

UPDATE: Zurb’s Verify has been heavily covered in the press here: TechCrunch, NYTimes, RWW, TNW.