Andy Finnell has written a great blog post discussing iPhone app pricing. I found that his average of 16 sales a day for a non-free application is exactly on target. That’s the usual number I see for iDjembe.
On the other hand, ICanHasCheezburger, which is free, sold about 4500 copies on Nov. 13, when it was #74 on the top 100 free application list. Since then it settled down to about 2500 on the 15th. If #74 sells 4500 copies, the top free application must have sold at least 10,000 or more (my guess).
Free applications will always sell more than one that costs money, but I’m sure a top selling paid application could easily sell over 1000 copies a day. Most paid applications are nowhere near those heights.
I have no intention of quitting my day job to write iPhone software, though. I priced iDjembe at 0.99 because it’s a simple app and I just wanted to get something out there, although I am planning a big update. I won’t release it until after the update to ICanHasCheezburger and a new application I’m developing that will be associated with a particular website.