Emphasis added. We were previously talking about mid to lower tier artists. I will concede (and have previously stated) that top stars have always made money from album sales as they had the power to get more equitable contracts.
Not sure exactly how it worked but many artists talk about getting a check directly from iTunes.
I would assume the increase in revenue from that stream had something to do with the ability to monetize individual songs without what would essentially be the full production cost of the physical object. I can’t imagine back in the day that singles were a lot cheaper to manufacture than full albums in any physical format.