User blog comment:Jimeee/Elder Scrolls Online will be subscription based/@comment-24770123-20130903023055

4 types of MMOs:

One-Time Fee: Buy and then play for free, sometimes microtransactions and expansions. (GW2)

Free to Play: Totally free exceot for shortcut microtransactions, etf. (Planetside 2)

Subscription: Can only play with subscription (WoW, ESO, Asherons Call)

Pay to Win: Usually called free to play, most features require you to pay. (POTCO, SWTOR)