One of the big psychological traps in purchasing goods is the pricing and discount. The users want to spend the higher amount on that discount, but might not be able to accurately gauge how long bits might last and/or the rate at which they use them. It's similar to when we learn how to gauge value versus real world money.

That being said, there is an often missed opportunity, the "2nd Chance" or less favorably called "Instant Regret".

The idea is that a user purchases less than they actually wanted to buy, not being able to accurately gauge how many they need. This makes it a harder uphill battle to convince a user to shell out more additional bits without feeling slightly ripped off, the sensation of instant regret when not buying enough. In order to bridge this gap, you implement a 2nd chance offer. Within 24 hours, you can get a partial deal on increasing the amount of bits you purchase. Lets say you select the 10,000 bit option, and the user blows through them, they may feel mental pressure to not purchase additional, but wish they would have gotten the better deal at the 25,000 bit option. The 2nd Chance could work either as an inbetween (instead of giving the full 12% off, it gives 11% inbetween the 10k and 25k bit option, enticing the user to maybe pick up more at a discount.), or the better option, within 24 hours you can take advantage of the full discount including on the amount previously purchased. It could even give a pop up for users after about an hour (depending on analytics to see how fast on average the users spend bits after purchasing them and almost deplete them) that offers the additional bits, along the lines of "Hey, you have 22 more hours for a 2nd chance on the {insert larger bundle of bits one option above} at {#}% off, saving you a total of ${###}".

Something to that affect. It would both push bit sales, while favoring users as well, giving them a better experience while also getting a few more bits than people might have bought on their own. It is still their choice, and its just offering the deal that was already in place, just a better way to interact with it for those users that feel that instant regret of not purchasing more at the better rate. Feel free to reach out if this isn't the right place for this sort of suggestion.