email, mobile, social and various types of paid search or paid traffic in general, CPV/ PPV being my favorite paid type search marketing. Of course any type of marketing that helps increase my revenue is my favorite.
I have tried several marketing techniques over the last several years and the best for me by far are: Social Media, Forums, and Blogging. Other methods such as SEO takes a lot of time to master(plus completion is ridiculous), the methods I mentioned earlier are definitely the easiest/cheapest especially if you are a beginner. GOOD LUCK!