Mobile marketing is a very cheap and lucrative form of marketing. With the latest mobile phones people can view information in pretty much the same way as using the internet and therefore can see advertisements also, similar to the many Google ads that you see all over the internet.
Mobile marketing isn't free but its much cheaper than internet advertising. Basically the idea is that you build ads where by you can specify exactly what sex, age group, interests and so on apply to your target audience, you can even target all mobile devices in a specific location at a specific time. The traffic generated via your ads can then be directed to an affiliate product related to the interests of your audience or it can be used to capture email addresses that can then be used to promote multiple offers or affiliate products.
One of the latest mobile training products available is Local Mobile Monopoly, you can see more about that here: