jubna and speakol already covered so i wont beat that horse, but one thing on the payment side that got mentioned... watch the FX too. some of these networks bill in usd while your offers pay out in usd but your testing data is all gulf, and if youre topping up from a weak currency the deposit fees and conversion eat into your test budget more than people realize. small leak but it adds up when youre throwing small amounts across angles.
also agree the lander is where it lives or dies. one thing nobody said, ramadan completely changes behaviour. weightloss especially, the angle that works in feb is dead during ramadan and then goes nuts right after eid when everyone wants to drop the weight they put on. i schedule around that now instead of fighting it. if youre testing during the wrong window you might write off a good offer for no reason.
speed thing someone said is real too, dont sleep on it.