All this craziness for less than 67 cents per day for most all users. Truly amazing.
The expectation, of most, was when purchasing X3 in September 13 that X4 would be released 12 months later.
We got 6 months of updates: a six month period of program update support. and 10 additional months of general support before the new version was released. So we got 16 months for what most expected to be 12. Great deal?
So, most users purchased the usual 1 year subscription, paid in advance, just like most subscriptions.
Call it whatever you want. But do not confuse the option to pay monthly with the reality that for years we have purchased a 12 month subscription.
General definition:
"the action of making or agreeing to make an
advance payment in order to receive or participate in something."