I know 280 robux makes one ad credit, which is aproximately 3 dollars; but I can’t figure out how the exchange rate works. 0.01 USD is the minimum max bid, and 0.01 Ad Credit is also the minimum max bid. So if an ad runs at a max bid of 0.10 ad credit, and a competitor runs an ad at a max bid of 0.10 USD, which one is deemed more valuable?
1 Ad Credit = 1 USD.
Subsequently, 0.10 ad credits is equal to and just as valuable as 0.10 USD.
You mentioned in your post that 280 robux makes one credit, however you say that it is approximately 3 dollars. It isn’t - it’s approximately 1 dollar, assuming devex rates.
What you are MEANT to do is to directly deposit money into the ad manager, and not buy robux as a middleman. The robux option is mainly meant for ‘larger’ developers so they don’t have to cash out just to reinvest it in the game.
Is there a difference in conversion if you use earned Robux from your game and purchase Ad Credit with those? Is it worth holding on to some Robux you earned on your game, or might as well do a payout of that Robux to USD and then decide on ads.
Depends on what method you used for receiving the USD. Most methods take a (small) % of your money as a fee, so it would probably be better to do Robux → Credits rather than Robux → USD → Credits