What I've been doing for some time now is simply putting things on my Wishlist and let them sit until something is at least 50%.

I've no actual idea what the arrangement between the artist & distributor is. But using the practice of movie distribution as an example, and a what number of similar business were modeled after, a first run movie's box-office take was split 90%-10% for X number of weeks; the lions share going to the distributor. The 10% and concession sales went to the theater.  As time went on, the percentage leveled out or even re-balanced in the theaters favor, but audience sizes would be dropping as well.

Might not be as flashy as the first days number of sales, but the artist usually makes a better percentage the older the product is. They're digital assets, so for the Distributor, the only real cost is maintaining server storage. So for them really it's, pretty much all profit.