An Ad Campaign is another way to reach your target crowd. Although a good SEO will get more clicks, it is hard getting to the top of the search results, and is sometimes a way to promote your product. There are many networks that offer placing ads in them. The most famous ones are Google and facebook. Caution is advised for all networks and especially these two, since their interest is getting more clicks and an inexperienced customer will pay a lot on empty non relevant clicks.