Every product needs a believer. Not on the product team, but outside. A champion beta tester. Someone who sees the potential and will offer such constructive criticism and feedback early on that if you don't make the app perfect you will be personally letting them down.
This is so critical, that many products succeed or fail to reach 1.0 on this point alone. Without inspiration from your peers, it becomes difficult to push through the dip, the rough times in development when everything goes wrong and you can't imagine how your app will ever see the light of day. Seek out that one person — friend, spouse, blogger, anyone — who will light a fire under you to ship a quality product.
Yes, I want to hear how much you like my app, but I also want to hear where it fails and frustrates you.
The feedback I've received for Clipstart is astonishingly well thought out and helpful. I like to think the app is attracting the best kind of customers: articulate and experienced enough to know what they want. If I could only implement half the suggestions to improve the app it will evolve into something great.
Of course, great beta testers only go so far. We still have to work really hard. Merlin Mann said it best: "The only person who can sit on your ass is you."