Subscription models are a complex thing to make work in today's video gaming space. At one point, they were the only way to keep massively multiplayer online games running. Games like "Everquest" and "World of Warcraft" thrived on that model.
Believe it or not, that was about a decade ago now. Most subscription based games go under relatively quickly these days...with the exception of the aforementioned World of Warcraft which seems like it will outlive the human race and/or cockroaches at this stage of the game.
Most MMOs today sustain themselves on the dreaded "free-to-play" models with games like "Planetside 2" and "DC Universe Online" doing rather well for themselves. That's why many people in the know were surprised when Bethesda's "The Elder Scrolls Online" announced it would have a high retail price ($59.99) and subscription ($14.99) on top of that. Unfortunately for the developers, that's gone over as well as the proverbial lead (led) zeppelin. The game has had a steady player base, but its overall numbers have been far from stellar.
With that in mind, it seems as though the game might be positioning itself to explore free-to-play as it has abruptly stopped offering six month subscriptions. As noted by PC Gamer, when this was brought up by the French forums for the game, a moderator said people just preferred paying for 30 to 90 day subscriptions, so they got rid of the 180 day option. For now, I will take that at face value, but it does seem weird to limit the audience's choice if there isn't a plan in place to change the subscription model in the immediate future. Also, it was recently announced that ports of the game for the PS4 and Xbox One were going to be pushed back to the rather nebulous "sometime in 2015."
I gave "The Elder Scrolls Online" a whirl when it was in beta and found it to be quite promising. Transferring "Skyrim" play mechanics into an MMO is an enticing proposition. That initial buy in has always been a stumbling block though. I may give it another look if the game does switch to a F2P model and/or when it hits the consoles. I'm willing to bet many others will too.