Indeed that particular part of the law is a joke. However, also in Spain, things like advertising time for political parties on TV or on city streets are regulated so that each party gets a share of the space/time proportional to their last election results (and they cannot buy more advertising space/time than that, even on private media).

It's very far from perfect but it's at least better than an unregulated market where the reach of each party depends purely on money.

Unfortunately, I don't think the regulation covers social network advertising. As usual, the law lags behind technological changes.