Lol, I don't think any one interested in a life time subscription has any concern about cash flow.

And a lifetime sub is as simple as it gets... Remember all that hassle with switching to 30 day subs so you could keep playing and all the people who ended up having their game blacked out for days because they didn't follow directions exactly right? All that goes away if you only have to pay once. I don't know why you're connecting lifetime subs with paying gil for subs or having a cash shop... They're in no way connected.

It's just a different kind of sub.