As aggressive and as imbecile as anywhere, with a few local touches. Takes too much time on TV and makes radio nearly impossible to listen to. While there were a few ingenious and well done campaigns, which made their way into the folklore, achieving almost the status of a cult film, these were, unbelievably, mostly back in SFRY (which did have a market economy). Nowadays, it's the same crap as anywhere, without much local color.
There are billboards along any main streets and roads, specially at the edge of town. Then there are smaller ones on the lampposts along the boulevards (although these usually avoid places where the trees would hide them).
Junk mail is still not as ubiquitous. We are getting maybe one or two pieces a week, one from the local grocery chain (which we started avoiding for several other reasons) and one from a furniture outlet (which we never visited, there's a better one in the neighborhood). Then as any elections approach, there's a lot of leaflets from the parties.
Telemarketing is actually illegal, but people don't know it and nobody takes them to court. There's no do-not-call list, so you have to send them off on your own (some of them more than once) before they take your number off the list. We used to get a couple of calls a week for a while, now it's a couple of weeks between calls.
There's also the downright dirty practice of sneaking insurance with utility bills.