Id prefer to buy a second copy for my casual friends then

No. The problem is not the amount of money, the problem is the dependency. I want to be able to play my games independently of what any publisher/developer is doing after the purchase. A framework which requires a daily subscription fee also means that I'd be dependent on servers running, authentication servers not messing up, the publisher not suddenly raising the fee into astronomical heights, the publisher discontinuing the product, etc. I don't want that. Can't tell. I'd be wary of the slippery slope in such deals, on the other hand I might consider 25 cents "nothing" for a one-off experience. But it's a bit of a moot question - I'm mostly a single player player anyways, with my friends I do other things than playing computer games.

Not for my favourite game, no, but I would gladly do it when I get visitors and we plan to play some games together or for games that I expect to be very short and don't expect returning to again.

That's essentially a rental system (EDIT: seems others already pointed that out) - I haven't rented games in the past, but I also see nothing wrong with doing so and would support a rental system (at least morally if not financially) as long as the business model is upfront that games are being rented, not sold. This would be such a thing, so I guess I would be supportive.

I used to subscribe to Metaboli which worked out at the time to less than £1 a day - for any of the games on the site - as many as you like at any one time.

Not quite the same as you are committing to a whole month at a time - not one of payments for single games.

It worked OK for a while. Then I realised that with digital downloads, sales (and GOG) I could spend less and get a much more tailored collection. You were also completely buggered if the service (or your connection) went down.

A quarter a day is a very cheap rental, and I'd definitely make use of such a service. But if I found a game that I really liked, I'd probably rather buy it. So yes, but not my "favorite game."

Remember that Christmas someone forgot to pay the domain renewal and customers were left without games during the holidays ? Good times ;)

There was a game that tried something similar, you paid per hour to play it.. I think it was APB.

It makes sense to an extent, as does this idea, that you only pay for as much as you play.

Now, would I do it? I dunno, it would depend on how it was done. $.25/day? Sure, because then if I play it every day for a month, I'm still paying less than standard MMO sub rates.
$.50 or less per day, I would consider for a game I liked. Above that I would quickly start looking for an alternative payment scheme, unless it was like you mentioned a "Every Firday night" deal..

But if I otherwise wouldn't play the game, I probably wouldn't play it Friday nights, either. >.>

A quarter per play session / day is a lot better than paying stupid subscription fees for MMOs. What happens if I don't play for three weeks? I still have to pay the $20 monthly fee. *shrugs*

No. Two problems:

1. I usually would rather just buy something outright where it's a viable option. It usually works out cheaper in the long run. I might be tempted to spend 20p to try a game I liked the look of for a night though. That's really not such a bad idea. But for a game I already know I like I'd want to buy it. Not least of all because it would mean that it's not solely available as a rental.

2. The game could be killed at any time. Any game that wasn't raking in enough money anymore would simply be killed off. So you would never see a game that uses this model appear on GOG. It would have all the disadvantages of an MMO. It would also give publishers full control over pricing. Normally games drop in value so fast that even by the time they're released the price has already dropped quite a bit. Would there be a point where this game was put on a lower price point? No. They'd just kill it off.

Generally speaking I just don't want any system that gives publishers more control over the games than they already have. We've all seen what they're inclined to do with the control that they have already, so who the hell is going to be naive enough to trust them with more?

No. If a game was a "favorite" I would probably already own it. And I definitely wouldn't pay to experiment with other games.

If it was that important for my friends to have me play with them, I'd tell them to buy me the game. :-)

I bet I know someone who would

An interesting question. Some 30 years ago, with 80's money, i was pumping quarters into arcade machines. i'd labor, get paid, then convert $10 of it into a roll of quarters to get a few hours worth of gaming. Fond memories of that. But i wouldn't do it now, not even if i didn't have my own arcade, by way of PC games.

Well... yeah i do want to hang out in an arcade again. Play some Tron in one of those surround sound cabinets, and revisit some other old classics. Fun times, i want to revisit those memories, but just can't imagine paying for play on a regular basis.

I think rent-to-own could have a big place in digital gamings future.