Good stuff. We're at step #3, and we're trying to strike the right balance between gathering customer feedback (which brings waves of great ideas) and making sure we're delivering only what we need to learn quickly. Step #4 might be the hardest so far.

On that note, anyone interested in helping us with StartMetrics (http://startmetrics.com)?

It's a service that tracks lean startup metrics for SaaS products. We're currently inviting folks to sign-up for the beta test when it's available. We'll also be sending a few customer development surveys.