Still think mobile has no relevance to your e-mail marketing program? Think again. With more than 250 million wireless users in the USA and more than 3 billion users worldwide, mobile phones have reached mainstream status. Sales of smartphones — those capable of receiving e-mails and browsing the Web — are not only expected to outpace regular mobile phone sales but have exceeded the sale of laptops since 2007.

Lower prices, smaller devices, richer capabilities and the phenomenal hype around the iPhone have helped propel smartphone adoption. If you are still under the impression that smartphones are just for the business elite, look around next time you are at the bus stop, on the subway, or standing in line and you'll see that smartphone usage is crossing gender, color, age and economic lines.

Smart e-mail marketers already know that their e-mail does not render the same in Hotmail as it does Yahoo or Lotus Notes, and have invested in optimization solutions to ensure a consistent customer experience from one e-mail reader to another. However, if you ask the average e-mail marketer what their customers' experience is like on a mobile phone, you are usually confronted with a blank stare followed by some mumblings to the effect that they don't do MMS/SMS. When you clarify that you are talking about their customers who are reading their e-mails on mobile phones, their response usually falls into the category of “We can't track it so we don't do anything.” Sounds a lot like “what you don't know can't hurt you.” But it can.

Cross-platform portability of your Web site and your e-mails should be a priority if you plan to compete in the 21st century. Unfortunately, e-mail capabilities on mobile phones are even less consistent than those on a PC with Symbian, BlackBerry, Palm, Windows Mobile and the iPhone all providing very different e-mail environments. True, real cross-platform portability e-mails will not be achieved overnight, but with the right solution and expert guidance, you can begin taking simple steps right now that can dramatically improve your customers' mobile e-mail experience.

Screensizes matter a lot as it directly impacts what renders in the first screen and how much scrolling is required to get to your branding and calls-to-action. While BlackBerry, Palm, and Symbian don't render images in their e-mail readers, the iPhone has them on by default and Windows Mobile 6 allows you to turn them on or off, so look into image rendering.

Also, pay attention to the whole message. While this may seem obvious, some solutions only show you what displays on the first (tiny) screen and do not permit you to view your entire e-mail on the mobile phone. Look for one that allows you to scroll through the entire e-mail on the mobile phone just like your users do. After all, if the goal is to optimize their experience, it's important to understand what their experience is first-hand.

If you cannot access a solution through any of the aforementioned resources, consider investing in a BlackBerry if you target primarily USA customers (BlackBerry has 41% of the US market) or a Symbian based phone if you market internationally (Symbian has more than 80% marketshare outside North America). The bottom line: Your customers are likely going mobile whether you like it or not. Isn't it time to wake up and embrace it?

Deirdre Baird is president of Pivotal Veracity. Reach her at dbaird@pivotalveracity.com.