You could hype up digital releases (as let's be honest when was the last time you bought an actual music CD). In my opinion, hardcopy CDs should be more popular among hardcore fans as it could be considered "merch."
I think hardcopy CDs are still reeeaaally big in Japan. Still, more promo options for digital releases would be cool- they wouldn't even need to be free, you would still be paying for the advertising, which keeps the balance of only having one no-cost marketing option.
