This is what was discussed a few days ago here: http://news.ycombinator.com/item?id=3649828

Joel Spolsky's blog post, mentioned in the discussion, is worth a read too: http://www.joelonsoftware.com/articles/CamelsandRubberDuckie...

And so is this post: http://blog.boundary.com/2012/03/02/selling-in-2012-its-comp...

As the later says, it's complicated. Personally, as most of HN readers I guess, I also can't stand this sales model. But some buyers demand it. And they happen to be the ones with the most cash to spare.