In the book Ubik (if i remember correctly, been reading too many sci fi books lately that i might confuse a few) there's a nice description of how micro transactions would look like in real life. in our real life, you can already pay to upgrade your clothes (obviously) and status, you can pay to upgrade your appearance by having plastic surgery, you can cut through diet by having/purchasing stomach stapling which increase your health, agility, charisma etc. you can pay to improve your vision. in the extremely close future, we could also pay to upgrade other stuff as well.
In the book, the concept is more about free to own, pay to use. the characters gets everything for free, but they pay a small amount for the usage. they have to pay to open the fridge, use the phone, open the front door, pay the coffee machine etc.. reading it is very much reading a dystopia since the people don't actually own anything and have to pay just to keep the basics operating, but it actually could be a viable alternative paying scheme for short term living. instead of having to either buy a house or pay rent and buy everything else, people would get everything for a lease for free and pay for the volume of usage. for a student that spends most of his time away from his apartment or a businessman that works 12 hours a day and has to travel a lot, it could be a viable option. obviously for the long run it wont be, but people could make that decision themselves. it obviously can't totally replace ownership, but as a niche paying system it could have merits.
Btw, once self driving cars really kicks in, which isn't far off from now, car ownership would gradually be replaced by Uber like services that operate robotic cars and car usage would be similar to microtransactions: Wanna take the shortest path? pay more. wanna travel alone? pay more. wanna travel with only women (For other women)? pay more.
But, yeah, the tolls and fast lanes charges are more similar to what micro transactions does in games, the Ubik description is more like an Onlive platform for real life. i wonder if such paying scheme for a local game would be attractive: you d/l the game for free, play once for free and then after the second launch, or after a set period of time pay like 0.1 for every relaunch and 0.5 USD for an hour of play time. for an AAA game like Civ 5 it could actually be more profitable for Firaxis and for the players, where the casuals pay less and those who didn't like it probably wont pay at all, having the more dedicated plays pay the lion's share.