Alex Denning shares a number of lessons about (in his words) “failing to sell WordPress themes” during the gold rush (which he defines as about six years ago). I think there’s something in this post for anyone, even in today’s market.
I found his two financial mistakes particularly applicable: (1) not buying software that made purchasing a good experience and (2) not offering refunds. Also key: “..make people excited about your product in the run up to its launch.”