Spamming is a bad thing and a sure way to NOT get players to your site. There are lists available to purchase everywhere on the net. It is imperative to ensure they are double opt-in and always check references before you purchase anything from a supplier. Emailing your own members about offers and news is a good way for retaining your customers.
If you find a list you think is good true to be true, it probably is. Best to ask around before you invest.
M.