Between the rapid rise of foursquare and Google's new check-ins for Latitude, Brafton has reported that marketers should get their brands on location-based services' maps. Now, it seems there's a new location-based app marketers should watch – shopkick. The company announced today that it has received more than 100 million check-ins in just six months.

Shopkick is a mobile app that offers users rewards for checking in at stores, scanning products or – in some cases – simply for walking into shops. Users get “kickbucks” for certain activities, and these bucks can be redeemed for rewards, including iTunes credits, meal vouchers, gift cards with participating brands and products.

The app was launched in August of 2010 and it has already garnered more than 750,000 users. In addition to its 100 million check-ins, the company says each day thousands of its users physically walk into partners' stores. While users can manually check-in, the walk-ins are calculated only when the software detects a users' presence inside the store. Marketers may like how this app enables them to offer greater rewards for walk-ins, as these are the customers who pay off.

“The economic value of a walk-in is 200 times the value of a check-in, according to our data,” says shopkick CEO Cyriac Roeding. Roeding also says that there are more than 1,100 retail and 100 mall locations in the company's partner network already.

Shopkick is still a startup, but it may be one location-based service to watch this year. About 10 percent of the app's users are active every day, and nearly half are active on a monthly basis. Marketers will want to be on the lookout for other rising apps and social networks in 2011.

As Brafton has reported, comScore's 2010 Digital Year in Review indicates that a number of startup services are gaining influence among consumers. Nine in 10 consumers now visit social sites each month and some unknowns are making their way onto the charts. For instance, Formspring.me showed year-over-year growth of 1,000 percent, hitting 5.3 million visitors in December.