Totally agree about the weekly emails. Unless I was using stock photography all the time (in which case I'm less likely to need the free ones) this would be no use. I was searching urgently for a good free stock photo a while ago and these sites just made me screw my face up.
To make matters worse, there doesn't even appear to be any way to get the back-catalogue of most of these sites. Death to Stock gives you a collection of photos when you sign up, but it's just 10 sample images.
Very confusing.