In the UK this is regulated spend, except the rules weren't updated for social media and all sorts of dark money adverts started appearing. The UK system gives

In the UK this is regulated spend, except the rules weren't updated for social media and all sorts of dark money adverts started appearing. The UK system gives both a minimum and a cap. Parties are entitled to a TV slot and I believe each candidate gets a free constituency mailshot as well. Beyond that the amount of money that can be spent is supposed to be capped.