As of today, adverts started appearing in Nokia Weather, always for Pizza Hut, so this company is presumably the first onboard with the new ad system or at least the first to get processed. When tapped, full details for the (in this case Pizza Hut) outlet are shown, along with a downloadable voucher, web and phone links, plus a Nokia Maps button, so you can tap this and then choose to navigate etc.
Aside from the erratic nature of the ads showing up in the first place (no doubt there's an algorithm being worked on) and the single company advertising so far, it seems the database isn't yet vast either, since there's a Pizza Hut takeaway depot about 200 metres from my house - you'd have thought that this would be worth a mention rather than just the restaurant over 3 miles away?
Although I'm not generally a huge fan of in-app advertising because it's usually fairly generic in its targetting, location-specific adverts do make much more sense.
You have to wonder though - if this code is in Nokia Weather, is it possible that similar code exists in Nokia Maps, Nokia Public Transport and even Nokia Drive? And would this be a good or bad thing? Comments welcome.