With mobile expected to play a larger role in consumers’ shopping and purchasing activities this year, it is more critical than ever for retailers to deliver high-performance mobile experiences or else risk losing customers to those who are.

Mobile has exploded in the past year, with more consumers owning smartphones and using them for a growing array of activities. However, the number of mobile retail experiences has also grown significantly – optimized sites, native apps, hybrid apps, tablet sites and apps – challenging retailers looking to provide an optimal experience for users.

“What we see with a lot of our retail customers is that they have multiple applications that they have to deal with,” said Rachel Obstler, senior director of mobile product management at Keynote, San Mateo, CA.

“A retail customer could have a Web site that is not optimized for mobile but which mobile users are visiting, then they have a mobile-optimized version and they have a mobile app, so they are dealing with three different applications.

“They may also have HTML5 to deal with and if they have native apps, they have to deal with iOS, Android and other platforms,” she said. “There is a lot of complexity there.”

Dealing with fragmentation
In general, retailers appear to have upped their game significantly in the past year when it comes to providing a strong mobile experience across devices.

However, there are a couple of potential pitfalls for the upcoming holiday. One is the release of Windows Phone 8 at the end of this month. If sales of devices built on this new platform take off, retailers may find themselves scrambling to provide optimized experiences for them.

Additionally, the new iPhone 5 – which is selling briskly – has a larger screen and many retailers have not yet updated their apps to fit the new size.

Finally, the number of tablets in consumers’ hands has grown significantly and the device is proving to be a popular shopping tool, yet many retailers have not yet developed tablet-optimized experiences.

Retailers recognize the need to test and make sure their mobile experiences work across devices, however they may not know the best way to go about doing so because there is so much fragmentation.

Quality experiences
Since it clearly not possible to test that a mobile site works across every mobile device out there, there are several ways retailers can go about figuring out which devices to test for, per mobile and Web site testing and monitoring company Keynote.

One is to pick the top 20 devices. However, this may not take into account all of the different aspects of devices that may impact the quality of the experience.

Therefore, Keynote recommends retailers choose an array of devices using different versions of an operating system, with varying screen resolutions and other aspects that may affect how their mobile experience is delivered.

“If you want to make sure your application is going to good quality, you have to test but retailers typically don’t have the time to test on every single phone out there,” Ms. Obstler said.

“It is very important to try to rationalize the set of phones you are testing across,” she said. “One way to do is to think of the key criteria that will affect the quality of the experience.”

Keynote also offers a free online tool that provide a list of devices retailers should test across based on a set of criteria they input. The free Device Planner tool be accessed at: http://tce.deviceanywhere.com/home.

Fast times
When it comes to optimizing the performance of their mobile site so that the experience is fast, even on the busiest shopping days during the holiday season, there are several steps retailers can take.

The idea is to reduce as much as possible the amount of communication that has to take place between a device and a retailer’s Web servers. This means avoiding redirections as much as possible.

Additionally, retailers should reduce the number of separate domains on a page and the overall number of requests.

“We recommend that retailers try to deliver a page in 10 or fewer roundtrips to the server,” said Ken Harker, senior manager of mobile performance at Keynote.

 “This means you have to be disciplined in what you are delivering,” he said. “It can be very difficult for companies to focus on what is most important that needs to be on a page.”

One tactic is to reduce the number of images that need to be refreshed.

If there are a lot of small images and icons – elements that are always going to be on a page and that are not dynamic – retailers can combine them all in one Cascading Style Sheet instead of serving them in separate style sheets.  This will result in only one roundtrip from the server and can be a lot faster.

Performance improves
Another technique that retailers are using more often is converting image files into a stream of text using Data Uniform Resource Identifiers, or Data URI. This will not work for images that appear on more than one page because the image does not get cached separately.

However, if the image is appearing on only one page, using a Data URI can eliminate the need for a roundtrip to the server and speed up the experience.

“I’ve seen a lot of improvements in the past year in performance,” Mr. Harker said. “It used to be that retailers’ mobile sites would become slower every day during the peak hours of the day but that has improved over the past year.

 “As we get closer to the peak shopping season, retailers are interested in making sure their sites are up, available and not slowing down,” he said.

 “There are populations that are going to have their first Internet experience be a mobile phone. Retailers that give a bad experience because they have not spent a lot of time testing are not going to get another chance with these consumers.”

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