The Mobile Communications article, Why retailers need to be mobile for the 2010 holidaysincludes a lot of compelling reasons for taking your sites mobile. I pulled together a list of six reasons from that article plus a few other sources so you can see the full argument here in a quick, handy list:

1. Retail sales for mobile commerce in 2009 grew 117%, up from 57% in 2008, and will continue to increase throughout 2010.
2. For the first time there are more smartphones than desktop computers being sold, according to IDC.
3. The sheer number of smartphone users has more than doubled, and Digby expects at least 65 million more to be enabled by year’s end.
4. The average mobile subscriber is age 25-34 and nearly twice as likely to make more than $100,000, according to NielsenWire.
5. Mobile represents an additional revenue opportunity because people can buy anytime, anywhere and immediately – allowing retailers to capitalize on impulse purchases.

And number six….. data collection.

Companies can gather a treasure trove of information including product views, pages users linked to, exit points, purchases, and product feedback shared with friends during chat sessions.

The question is, how do retailers use social media and mobility data for better merchandise planning? At NRF Tech on Aug. 16, SAS’ Greg Soussloff is hosting a roundtable with some of retail’s top IT executives to answer that question. He’ll report back with ideas from that discussion, so stay tuned…

In the meantime, check out a real-world example in this article detailing how Wet Seal’s social media and mobile activities have impacted merchandise and assortment planning. The junior clothing retailer’s online fashion community allows users to build, tag, share, rate and purchase outfits through a personalized virtual boutique. This user-generated content is placed directly into the online and mobile purchasing processes. Search for a pair of skinny jeans, for example, and the top-ranked user-generated outfits containing those jeans pop up.

By analyzing the online outfits and ranking data, the company can discern trends, see customer sentiment about its products and translate that into better merchandising decisions.