Hello,
1st you will have to buy the initial allowance to play the game,
2nd you may then buy the game, but pay a monthly fee for using,
3rd it will install Starforce Mk XVIII on your PC which will install itself in the eproms of your motherboard and can never be deleted again,
4th you will pay for every upgrade like snorkel, decoys, special torpedos etc.,
5th certainly also pay for every other type of U-boat,
(5 1/2 for another face of your captain's avatar)
6th you need a permanent physical direct line connection to the Moscow KGB server, or maybe to Beijing,
7th you will certainly be online all the time, but especially when you are doing online banking with your PC.
Ahem.
Maybe this gives the Devs some ideas to think of next

,
the WW1 sim "Rise Of Flight" is already heading in this direction

What i really think is some kind of short online check every now and then, like in SHIV - anything of the points mentioned above and they will lose me as a customer - however i sure think they will use more usual and contemporary methods
Greetings,
Catfish