I imagine they spent a lot more on advertising their anti-"piracy" message. Compared to that, the ROI is probably pretty good. I therefore expect the lawsuits will continue, more's the pity.
What's interesting to me is that at least in the UK there's been a noticeable shift in the anti-piracy message.
Most telling is the anti-piracy ads in cinemas. (EDIT: I realize RIAA deals with music recordings only, and that it's the same for their UK counterpart; the ads used to be pretty much the same and the shift has been much more dramatic for movies)
A year or so ago in the UK the cinema's were full of "if you pirate you support organized crime and terrorism and you're pretty much satan" messages with ominous music and threats about how you'd get thrown out and more if you dared bring out any kind of recording device.
Now it's "thank you dear, nice customer for coming and paying to see the movie and helping us make more instead of pirating"... It's almost creepy what a turnaround it's been.
Maybe my long tradition of raising my finger at the old ads had an effect, or maybe some execs have finally realized that antagonizing your paying customers isn't as smart as it seemed to them at first.
