• by Mark Walsh  @markfwal, November 30, 2011

Highlighting the uptick in mobile shopping this holiday season, mobile ad network Millennial Media had its heaviest traffic ever over last weekend. Fueling the surge were mobile users researching products and seeking out Cyber Monday deals. The increased activity also likely reflects ramped up holiday advertising by marketers via mobile platforms this year.

Marcus Startzel, senior vice president of sales at Millennial, said between 20 and 30 campaigns began running the day before Thanksgiving and will continue until the Friday before Christmas. Retailers made up half of the top 20 advertisers on the network during the long holiday weekend, and campaign budgets are up 10-fold over the same period last year, he noted.

“Retailers are really catching up with the mobile curve and starting to understand how to interact with consumers on their devices,” he said. In particular, big retailers were relying on mobile advertising more this year to build awareness about special offers on Black Friday and Cyber Monday.

Data released earlier this year by Millennial showed department stores were the biggest retail advertisers on its network -- representing 22% of spending, followed by electronics and home and garden retailers, each claiming a 17% share. 

Research released earlier this week by IBM’s Coremetrics showed the percentage of people who used a mobile device to visit a retailer’s site on Black Friday increased to 14.3% from 5.6% last year, and to 10.8% from 3.9% on Cyber Monday. Meanwhile, mobile sales on Black Friday jumped to 9.8% from 3.2% a year ago, and to 6.6% from 2.3% on Cyber Monday. 

In another sign of heightened mobile activity, Amazon has said the number of U.S. customers who shop with the online retailer only via their mobile device had tripled from a year ago. In addition to retailers, Millennial said entertainment advertisers also geared up their mobile efforts last week to promote holiday movie releases. Recent major film debuts include “The Twilight Saga: Breaking Dawn – Part 1” and “The Muppets.”