Why not use HTTPS for everything?

Question

If I was setting up a server, and had the SSL certificate(s), why wouldn\'t I use HTTPS for the entire site instead of just for purchases/logins? I would think it would make

Answer 1

The biggest reason, beyond system load, is that it breaks name-based virtual hosting. With SSL, it's one site - one IP address. This is pretty expensive, as well as harder to administer.