When your supporter tag will end you will be old supporter what give you custom background, other chat nick color and beatmap submission limit change to 4-5 (or something like this).
But you will not get evrything (like only 1 more beatmap listing or other nick color) and this can be if you buy supporter more than 10 months or something like thisCawub wrote:
This sorta would lead to people only buying support for one month and just keeping old supporter forever. The features for supporter shouldn't be made free in a sense (you pay once and get the benefits forever doesnt seem right)