in past years whenever different scholars spoke at conferences/lectures etc sometimes it would be recorded, sometimes it wouldn't. no one could obtain the audio cassettes, nothing was available, quality was extremely bad. some scholars had jobs as imams here or there or would be studying overseas, but too busy to do anything else. over time many of the scholars with the ppl around them established foundations/schools... ie hamza yusuf has zaytuna, muhammad al shareef has almaghrib, faraz rabbani established sunnipath, sh mokhtar maghraoui has zawiyah and so on. so now the people around them try to record things professionally, edit and digitize them, they design the cd covers, pay for the reproducing, packaging, making them quality and sell them at perhaps a slightly higher rate than their cost to support their foundations. these foundations are non-profit.
so in one sense you are supporting the foundation, also the concept of imams/knowledge passed this way, and you are also supporting the whole industry of making quality recordings for dissemination and posterity.
i'd also say if you walk into any store and buy a cd -- instrumental or spoken it will cost you upwards of 15 bux, but for an islamic cd your average price will usually be less than that and it does go to a good cause.
as for those people who think "knowledge should be free" blah blah... i'd like you to support your family/foundation/projects with "free". k thanks
ps we've spoken about this topic at length...if anyone wants to dive into archives and search around...