Advertising for free means posting classifieds at no cost at all. A large category base makes in possible to post advertisements about most things. Services, things for sale, vet services, autos. property, events are just a few of the topics available. Ads are diplayed for 60 days, but you can extend this time for a small fee, or feature your ads for more exposure.
Search for local classifieds around the world - the great thing about free advertising is that it is not limited to just one country.