Good affiliate marketing businesses generate revenue 24x7, whether you are actively involved or not. That being said, they do not start out that way. The initial setup may seem like and insurmountable obstacle to many, but it is possible if you are ready for some hard work. Once you get the ball rolling. you can focus on growth and maintenance, which are generally much easier.
Yahoo Answers may sound like an usual place to market your product, but it somewhere people go to find solutions to their problems that ranks well in all the major search engines. Make sure your reply is actually helpful so it is not seen as spam. If you decide to place ads on the site, you will see a huge savings over the giant that Google has become. These answers get top ranking in Google anyway, so you won't be losing much by going through Yahoo.
Look into less popular social networks like Reddit. Don't neglect your Facebook page, but underrated sites like Reddit are not as flooded by the marketers and still have a large audience for your product. The little bit of time it takes to edit your pitch for this site will be well worth the effort.
Memes are one of the most popular web pastimes right now. You've probably seen at least one humorous captioned picture even if you didn't know what it was. Depending on your product you may want to create a Meme or two with it featured in the photograph. As it gets passed around, it will help create brand recognition for you. While unconventional, it may still work. You may even start browsing the web one today and see new Memes that people have created using your product.
While in most cases you want to keep things very professional, there are places where humor may have its place. Of course, if you are selling financial software to banks you won't want to lose your suit and tie image. On the other hand, if you are selling a product for home use, you could probably crack a joke or two and still do well. The goal is to create something funny that people will want to share with others, which then exposes your product to more people.
No matter how badly you want to generate sales, never, ever make false or misleading claims about your product. While you may get a few extra sales initially, at best you will lose customers because of your lies, at worst you could face legal ramifications. By honest and open about yourself and your product. If your product isn't very good, then you should be looking for a new product to promote.
These methods may not be common, but that is exactly why they can work for you. These are forums whose marketing potential is almost completely untapped. Concentrate on building your business using these methods. Later when you have a larger budget you can go after the bigger audiences.