Ad Words makes it so you pay only when someone actually clicks on your ads. You can set the amount you want to pay each day, so you'll never go over your budget.
Bing - Though Google is the king of the search mountain, it helps to reach out to all of your potential consumers. You may have more success with your desired demographic if you advertise on Bing.
Microsoft's search engine will give you a $50 credit when you sign up for its ad service. Just like Google, Bing users will see your business when they search for keywords that you set.
Bing offers several analytic tools to sharpen your results. If your ads aren't generating much traffic, try the SEO and Keyword optimization tools.
Amazon - Like search engines, e-commerce sites can be a great place to advertise. If you sell a product on your site, Amazon can redirect traffic from its store to yours.
This service is called Amazon Product Ads, and it starts you with $75 in free clicks. A link to your store will appear on product pages for items you offer. These are hyper-targeted - you already know that the customer is in the market for something you sell.