While the open rates for email via mobile devices jumped significantly in the first half, other findings in the report point to the need for emails to be optimized for mobile, according to a new report from Knotice.

The number of emails opened on a mobile device jumped 51 percent in the first half of 2011 compared with the last quarter of 2010, according to Knotice?s Mobile Email Opens Report: First Half 2011. The results also show that only 3.09 percent of the 701 million emails reviewed for the report were opened on both mobile devices and a desktop device.

?The percentage of emails opened on a mobile device jumped by 51 percent from the fourth quarter of 2010 to the first half of 2011,? said Patti Renner, director of marketing at Knotice, Akron, OH. ?Not only does this show an increase in mobile device adoption rates overall, it also shows that people are increasingly using the convenience of mobile to manage day-to-day tasks, such as checking email. 

?Email continues to anchor many direct digital marketing campaigns, so as more and more mobile devices find their way into consumers? hands, those mobile email open rates will continue to climb,? she said. ?This creates an opportunity for brands to stand out, to optimize for mobile and connecting with consumers on a more personal level.?

One chance
By operating system, iOS and Android lead with 12.78 percent of first-half mobile email opens taking place on an iPhone, 3.92 percent on iPad and 3.15 percent on Android.

Some marketers do not optimize email for mobile because recipients can reopen an email at their desk if the mobile email experience is poor. However, the reports results suggest that recipients do not reopen emails on desktop if the email rendered poorly in mobile.

Of the 3.09 percent of emails that were opened on both mobile and desktop devices, one-third were opened on mobile first then viewed via desktop later.

?We were surprised that only three percent of commercial emails were opened on both mobile device and desktop, with only a third of those opened the email on mobile first,? Ms. Renner said. ?Those numbers were lower than we anticipated which is interesting.

?It really knocks much of the steam out of the argument that an email designed specifically for desktop viewing will be ?saved for later? if it renders poorly on mobile,? she said.

?The big message here is that marketers only have one shot with each email sent. Consumers have more choices when it comes to tools for engagement, so marketers have to be ready with a great email experience regardless.?

Click activity
The results also show that click-to-open rates for emails on mobile devices are far lower than the rate for desktop devices. 

By industry, the click to open rates ? a measure of click activity within the email once opened ? were 18.99 percent for consumer products, 14.32 for financial services and 11.57 percent for health care.

The lower rates compared to desktop suggests the need for email that is optimized for mobile since it may be difficult for mobile users to take action on emails that have limited functionality when viewed via a mobile device.

?While mobile email opens rates are strong, the click-to-open rates lag far behind,? Ms. Renner said.

?Even if a person can open the email, the real measure is what they do once it?s open," she said.

?We believe the lower rates of click-thru activity reinforce the importance of optimization, as it may be difficult for people to take action on emails that have limited functionality when viewed via a mobile device.?

Final Take
Chantal Tode is associate editor on Mobile Marketer, New York