Nick Bradbury, creator of FeedDemon and TopStyle, announced after the tsunami disaster last week, that he would pledge to donate one week of his product revenues to the recovery effort. Yesterday, he indicated that he would donate $8,000 to the Red Cross as he pledged.
It appears that Nick just let us on to one of his secrets--the combined yearly revenues of the two products he sells. Assuming that $8,000 is representative of his weekly sales rate, then, his annualized product revenues are over $400,000 for his MicroISV operation. Of course, his pledge may have increased his sales rate, in which case the $400K may actually be upper bound. Since his average product price is anywhere from $30 to $80, but closer to $80, since his higher-priced TopStyle sells more better than FeedDemon, his unit sales are between 100 to over 200 a week (or $5,000 to over 10,000 annualized).
Nick's products have won a number of awards, but are somewhat specialized, limiting the potential size of his market.
Eric Sink, in his Business series in MSDN, reminds developers to avoid creating software targeted for other developers, since the size of that market is pretty small. For example, Lutz Roeder told me that he gets just 150,000 downloads a year for his free Reflector, a very popular .NET decompiler. It may be the most popular .NET developer tool.