MEDIAPOST — The expansion of social media on mobile phones is no secret. In a June report, comScore identified social networking as the fastest-growing content category across both mobile browsers and applications. And then there are the 100 million people worldwide accessing Facebook on mobile devices. The latest piece of evidence in that vein is a 50% rise in mobile ad campaigns that send users to multiple social networking sites in the last six months, according to the May metrics report released today by mobile ad network Millennial Media...

EMARKETER BLOG — In a push to promote its E-Class vehicle, Mercedes-Benz USA has made a few interesting forays into mobile marketing to help deepen engagement, loyalty and purchase consideration. Along with a sponsorship on AutoTrader’s mobile site, Mercedes also began running rich media ads on Motor Trend’s new iPhone app. I recently chatted with Beth Lange, a digital media specialist at the Mercedes, about the company’s objectives in sponsoring the apps and its mobile marketing goals...

FORRESTER RESEARCH — Foursquare, the geolocation social tool, has been a media darling as of late. Not only is it growing, but people innately understand the monetization model, which is not something you can say about every social site and tool. As people "check in," or report where they are to their networks, Foursquare serves them offers from nearby businesses. It’s a win-win-win situation: Businesses can market to people who are able to immediately take action; Foursquare earns revenue; and users get valuable offers they can use. But Starbucks’ current program on Foursquare may kill the goose that lays the golden eggs (or at least demonstrate how that goose may die a slow, lingering death of neglect)...

CLICKZ — Foursquare is dealing with a landslide of queries from business owners and marketing agencies that want a piece of the fast-growing service. Their requests are diverse: to validate a listing, create a special (i.e. promotion), score a custom badge, do coffee. The result has been long waits, in some cases three months or more, for businesses large and small. "It's not that we don't think your ideas are good, it's just that we don't have time to answer all of them," founder Dennis Crowley told a roomful of marketers at the CM Summit last week during Internet Week in New York. The number of queries to Foursquare now numbers in the hundreds each day. But the New York start-up is doing a few things to attack the backlog and streamline its processes, so relief may be in sight. It has also developed what it believes is a scalable approach to working with large brand advertisers...

CNET NEWS — Brand advertisers are flooding into location-based mobile applications -- from Foursquare and its ilk to custom-developed apps like Starbucks' store finder -- and while there are sure to be some laughably bad attempts in the mix, one industry that can jump into the "check-in" craze pretty safely is the travel business. Take this one: A niche check-in application for airports, GateGuru, just updated its iPhone app to include a new advertising platform that connects advertisers and marketers with frequent travelers...