I used to get kinda miffed that super popular restaurants like Border Cafe in Harvard Square do not take reservations, so you basically have to wait an hour or two to get a spot. But from their point of view it makes perfect sense. Why would they go through the trouble if they fill their tables at 100% with a line around the block to boot? That's how I think of the hiring pipelines as well.

p.s. Yes this is out of date somewhat but I promise Border Cafe was a hopping place 20 years ago :-)