Mistake #4: Directing users solely to your home page.

Small business owners are used to focusing on the message rather than where someone might end up after viewing that message.
Many think that their homepage is their most attractive and informative page and hope that users will find their way into the information they're looking for via it … so they direct all users to it.

The fact is searchers are an impatient lot, you only have about 5-8 second to convince them before they're clicking away from your site. If you force them to find their way to their destination instead of delivering them straight to the good stuff, chances are high they'll be searching for the back button and heading off to visit a competitor.
Untargeted landing pages can destroy the chance of a good conversion rate.

Solution:
Analyze your web site. Look for relevant content that you can use as landing pages. This content may not look as pretty as the homepage, but in PPC marketing, relevancy is more important than nice looking design.

For  example: If you're an ecommerce store, you might want to land visitors on your category pages.

>> Go to Mistake #5