By the way, I see from your past Ask HN submissions that in the past ~60 days, you've been thinking aboout "an opportunity in creating an ad network for a niche market" and looking for ways to accept payments for iPhone apps you've developed. Since your business here is apparently unrelated to these, I'll add lesson #3: if you're going to start a business, you must be 100% focused on that business. When you keep taking your eyes off the road, you're more than likely going to crash.