Comment by arjungmenon

I think at least for the initial startup period it would be a good idea to rely on Paypal or some similar service. The hassle of getting a merchant account might in some cases eat up too much of the founder(s)' precious time. Some successful retailers (like this indie game one: http://2dboy.com/games.php) continue rely on Paypal though they have a large user base. I think the best time to get a merchant account would be once the sales start rising above something like 10K/month or so. In that way, you'll (hopefully) have an account before your sales (again hopefully) hits 100K or so.