A good network takes care of you. I once dropped a new offer and got 4000 clicks and $0. I noted it to my AM, they pulled the offer (yanked the sucker), and credited me $1000. Now that's a partnership.
I personally find the only time to ask for a retro upgrade is if you normally get a larger paybump on all offers, and you happened to try an offer that rocked, but was on the cheaper payout, and you use it for leverage to your AM to do more. It's a simple game you play e.g. "Listen, I will hit this offer super hard if you can bump up the rate and take care of my initial tests".. usually they will.
Don't nickel and dime though. And follow through on your promise to your AM. Dont get a retro paybump and try another offer, reward your AM, and remember its a partnership.