In their continuing attempt to monetize the platform, Foursquare has just expanded their “Explore”-based self-serve ads to a few thousand small businesses.

Foursquare first launched Promoted Updates about a year ago, and up until June of this year the company only allowed bigger businesses to participate. In June, Foursquare launched a pilot program allowing a handful of New York-based small businesses to join in on the fun. Of course, we assumed that if that all went well, Foursquare would open up the Promoted Update ad unit to all types of small businesses – but they’ve just launched them even faster than I expected.

“The idea behind these new ads is simple – connect people looking for somewhere to go with businesses that want to drive traffic to their stores. Foursquare is the best way for those businesses to reach nearby customers. In our ad pilots over the past year, we’ve been honing our targeting technology, using the same algorithm that powers our Explore recommendation engine,” says Foursquare.

Foursquare says that they are beginning to roll out the self-serve ads to a “few thousand local businesses” today, and it’ll open it up to more businesses in the coming months. There are definitely a lot more businesses that’ll be anxiously awaiting their chance to promote themselves, just like the big boys. Foursquare has over 1.4 million claimed small businesses around the world.

If you’re looking to get on the list of small businesses that wish to start using Foursquare ads, check here. Businesses only pay for their ads if people visit (in person, or the listing on Foursquare) – an element of Foursquare’s advertising unit that they’re happy to promote.

Foursquare is early in the process of monetizing the platform . According to reports, Foursquare only made $2 million in revenue last year despite logging billions upon billions of check-ins and over 25 million registered users. By opening up these self-serve ads to more and more of the million+ small businesses on the service, Foursquare is adding a rather painless new money-making strategy.

Plus, I can even argue that this is good for users. Who wouldn’t rather see some promoted locations that are local businesses (especially when you’re talking restaurants), as opposed to the same ads for a bunch of big chains? I know I would. So far, Foursquare’s ad strategy has not been that intrusive, and it hasn’t really modified my experience with the service.

Last week, the company began a widespread rollout of another type of ad – the post-check-in ad, which suggests locations and specials after a user checks in to a nearby location. That type of ad, at least at its early stage, is limited to a few big-name partners like Toys R Us and Captain Morgan’s.

But it looks like July is the month – the one where we finally see Foursquare take some successive leaps in advertising.