I have used Google Adwords pretty much since it started. You used to be able to get a fair number of very targetted clicks very cheaply in Adwords by targetting

I have used Google Adwords pretty much since it started. You used to be able to get a fair number of very targetted clicks very cheaply in Adwords by targetting 'long tail' search terms. But Google have made that harder and harder over the years, for example by eroding things like exact match. Now it is pretty much highest bidder gets all the clicks.