That's not legal in Netherlands. You can easily cancel ages in advance (by law). The law was implemented because of too many shady behaviours by various companies.

Generally yes, you enter a contract for a 12 month subscription but get a discount for it (ex. paying monthly with no subscription it'd cost x, paying monthly with a subscription would cost 0.8x). Good services usually have a clause that you can cancel but have to pay a penalty (for example (number of months0.3x) or (number of remaining months 0.1x)).