For about the past three years, mobile marketing has been on the verge of breaking out and changing the way we interact with our target audiences.

That time has come. There are some strong signals that show 2011 should be the year that mobile finally “arrives” and makes a major impact on your marketing strategy. According to a recent Search Marketing Now Webinar on mobile trends:

• 49% of smartphone owners have purchased from their phones in the last 6 months.
• Mobile commerce is expected to reach $119 billion in sales by 2015.
• In 2009, 78% of marketers that experiment with mobile said their goals were met; 9% state that expectations were exceeded.

If you’re ready to go mobile with your business, one of the fastest ways to get started is through Google AdWords. And if you’re already running a PPC campaign using AdWords, the entry into mobile should be seamless.

Device targeting in Adwords

You might be shocked to hear that you may already be targeting mobile devices in your AdWords account. When creating an AdWords campaign, the default setting is to target all devices — this includes laptop and desktop computers, and all mobile devices.

I suggest segregating standard search campaigns from mobile campaigns. Their performance will differ greatly and the strategies employed to optimize both devices (computers and smart phones) will be unique to each. You can target specific types of mobile devices such as Android or the iPhone, as well as specific carriers such as AT&T, Sprint or Verizon. However, my company has not found a great amount of variation between AT&T users and Nextel users (except that the iPhone is on AT&T and now Verizon). When getting started, deciding which carrier to target is low on the list of priorities.

Website-targeted ads vs. Call-only ads

Once you’ve created your mobile-only campaign in AdWords, it’s time to start engaging with users on smartphones. There are a couple ways to set up mobile PPC ads:

• Send users to your mobile-optimized website. PPC ads can send mobile searchers to your mobile optimized website.
• Mobile users can call you directly from their Google search. Instead of sending users to your website, your PPC ad displays a clickable phone number and users call you directly from their phone.

Below are two examples of mobile PPC ads. One ad is focused on click-to-call — the only clickable element is the phone number. In the second image, the headline of the mobile ad is the clickable element, sending users to the website.

Choose the ad option that best suits your business objectives. If your website is not optimized for mobile devices, focus on generating calls. Also, if your lead close rate tends to be higher via phone, you may want to focus on click-to-call. To set up the click-to-call option in Adwords, enter the ad extensions tab of your mobile targeted campaign and choose to create a new Phone Extension.

Call metrics in AdWords

You also have the option to choose “call metrics.” Call metrics allows you to measure phone calls generated by PPC ads. Google assigns a custom Google Voice number for each campaign — calls to this number are rerouted to your business phone number.

The metrics provided with call metrics include:

• Total Calls: The number of calls to the custom phone number that was displayed with your ad on computer and mobile devices with full Internet browsers.
• Received Calls: The number of calls to the custom phone number that were answered.
• Missed Calls: The number of calls to the custom phone number that were not answered.
• Average Call Duration: The average duration per call received; in hours, minutes and seconds.
• Total Call Duration: The sum of the duration of all received calls.

To see these statistics in your AdWords campaign, you must activate the call metrics feature. These metrics can help gauge user interaction with your PPC ads on mobile devices, but you will need internal tracking mechanisms to measure the ROI of these calls. I suggest assigning a unique phone number to your click-to-call ads to measure leads and sales.

As of this writing, call metrics is free but this may change in the future. For calls initiated with a call-click on a high-end mobile device, the standard click charges will apply.

As you can see, mixing mobile advertising into your PPC campaign within AdWords isn’t a laborious process. However, pay close attention in order to set up your campaigns properly. If you send users directly to your mobile-optimized website, you should be able to gauge ROI similarly to your other PPC efforts. However, in order to determine the success and ROI of phone calls generated by your PPC ads, you need to have some sort of tracking in place. Now is the time to take action and get your mobile campaign running.

About the Author: Joseph Kerschbaum is Client Services Direct with Clix Marketing, a search and social advertising agency. With David Szetela, Joseph is the co-author of PPC Marketing: An Hour A Day, from Wiley/Sybex. Joseph speaks regularly at search industry conferences and his writing appears regularly in Search Engine Watch and the Clix Marketing Blog.