Who pays mechanical royalties?

The creators of a song - songwriters and composers - are entitled to receive royalties from digital reproductions. Stores pay royalties directly to a collecting society (e.g. AKM in Austria or GEMA in Germany). Those collectives pay the royalty share accordingly to all copyright holders.

Important:

In order to receive the mechanical royalties, you have to be a member of a collecting society. It does not necessarily have be in the same country where you live in. You can choose from collecting societies worldwide: https://en.wikipedia.org/wiki/Copyright_collective