Well, not every developer is making a ton of cash, and a fair few qualified ones may be quite happy to do an interview every day or so for a bit of extra cash.

Well, not every developer is making a ton of cash, and a fair few qualified ones may be quite happy to do an interview every day or so for a bit of extra cash. Heck, if enough companies offered $500 for a successful interview, some people would probably end up making more from going to interviews than they would accepting the offer.