We've been elbows deep in paid search projects lately - some that we've setup from scratch, others that we've inherited.  Paid search is a great medium for those who love numbers and stats.  Being able to track users from first click through conversion and backing out an ROI causes us to geek out a bit.  Here are the top five pitfalls we typically see relating to paid search that causes what could be a great campaign to sputter along in mediocrity.

1. Poor ad group setup
   Dumping keywords into a single ad group and not optimizing ad groups properly can cause quality scores to wane and CPC's to grow.
   
2. Too narrow of a keyword list
   Throw the net out wide and see how many fish you can pull in the boat.  Too many campaigns target too tightly and end up missing some low-hanging fruit.
   
3. No A/B testing of ads
   No brainer, right?  Use a champion/challenger approach and make sure you know what terms and copy are resonating with your audience.
   
4. Landing pages lacking clear calls to action
   Assume your users are idiots.  Place a huge and easy to recognize call to action right in front of them and don't make them work for it.  Keep is simple.
   
5. Haphazard bidding practices
   Blanket bidding across all phrases or overbidding on poor converting phrases can quickly zap a budget. 

There's obviously more to it that this, but these are a few of the more common mistakes that can cause your paid search campaign to live in mediocrity.  If you have a poor performing campaign, give us a shout and we'll help bring it from good to great.  Or bad to great.  Hopefully not great to bad, though.