Smartphones already make up 30% of the US cell phone market, and that number is expected to pass 50% by the end of 2011, if not sooner.  If optimizing your website and paid search for mobile hasn’t been a top priority before now, 2011 is the time to start.

The most exciting innovations happening in mobile right now incorporate the built-in GPS of the phone to provide highly relevant, location specific offers to give users what they want, where they are.  These types of ads are producing an amazing ROI at the moment, although it remains to be seen whether these stats will hold up as users become more familiar with mobile ads.

That’s why it’s even more important to start tracking and engaging mobile users today.  Here are a few tips:

• Track mobile visitors in Google Analytics (it can be found under Visitors > Mobile), and if your email subscribers are reading your email on their phones (litmus has a tool)
• Optimize email campaigns sent in the evenings or on weekends for mobile phones
• Begin using Google AdWords location extensions for hyperlocal ad results
• Consider creating a mobile version of your website if mobile visitors have a high bounce rate

Smartphone growth will only accelerate over the next year.  It’s time to fully embrace the platform, and provide users with engaging and relevant content when they’re on the go.