You should know that there are MANY other PPC advertising options available to you. However, Google is dominating the market right now and if you can pick only one PPC source of leads, make sure it's Google.

This graph shows the percentage of PPC search volume done on the 5 most popular search engines. It's very clear that Google is leading the way.

If you are interested in diversifying your PPC campaign, I've also had great success with Yahoo Search Marketing and MSN.