That's true, although while noticing the effect from a drug gets a good chunk of the way there, there's still a huge amount of effort after that which goes into

That's true, although while noticing the effect from a drug gets a good chunk of the way there, there's still a huge amount of effort after that which goes into getting it approved and to market. And vardenafil seems to have been researched purely with ED in mind. That said, ED isn't really a perfect poster child for the kind of medical research I'm talking about. It's just the best one to use with a one-liner because it conveys the point effectively, and because penises are funny. Other examples include treatments for male pattern baldness and second/third generation antihistamines. With the former, the pharmacological options are all again opportunistic situations, although the point about investing in getting them to market still applies. With the latter, that is not the case. And although there's no denying that they have vastly improved the quality of life for people with serious allergy problems, there's also no denying that the main reason for the investment put into them was helping people with the spring sniffles (as evidenced by the fact that their approved doses are set so low that they are barely of any use to anyone (otherwise they wouldn't have passed muster for "non-drowsy" so that they could get fast track approval from the FDA)).