While we're at it:
Promoting online operators without a domestic licence is explicitly outlawed in Croatia (but betting isn't). Still, there wasn't a single case where this law was applied and there are foreign operator ads on sporting events, and even on team shirts. The licence costs a lot, and whoever would get it would have to tax all money wagered with 5%, and tax the winnings over 100 € with a progressive tax ranging from 10 to 30% (the latter tax was introduced on April 1st this year but is no joke). The 5% tax on wagers, surprisingly, applies to sports betting only.
A foreign company can't apply for a gaming licence. A foreign company could open a domestic company though. Also, the brick&mortar and online licences are separate, and you need special approval for the online one. A thing to note is that the online services of the state-owned bookmaker close at 23:00, perhaps best illustrating all of the above.
In Bosnia there was a government decision - last year I think - to ban foreign online bookies, and the ISPs were ordered to ban access to gaming sites from Bosnia and Herzegovina. The decision fell the next day because of the protests and now the situation is back to the thing being illegal but the law is not enforced.
In Serbia I know of a case where a big affiliate was prosecuted in a widely publicised trial, several years ago, and as far as I know he unsuccessfully tried to prove he isn't accepting bets himself.
So I'm hoping the EU won't take the easy way out and officially allow each country to decide for themselves, otherwise in many countries we'll be stuck with a monopoly of domestic companies. Fortunately, there is very little understanding about online payments in general, and online betting and online wallets are rocket science to the politicians, and that's what's saving us. When they do turn towards "resolving" this situation though, we can expect a stupid decision, something like what Bosnia tried to do.
The laws of all three countries are against the general EU laws about monopoly. Countries are not allowed to ban foreign companies from operating on their territory. Licensing yes, but discrimination and bans have no place in the EU.
Professional bizdev can help you, the affiliate, to negotiate better terms with casinos. PM for details and a free evaluation of what I can do for you. All geos.