Location based apps have been catching on at an extremely fast pace. Foursquare and Gowalla lead the charge. However, a new type of location based service is beginning to take shape. Mobile shopping alerts are emerging in the location based arena.

Placecast and Shopkick are two new services that allow retailers to alert consumers of new discounts and coupon deals via their mobile phones. Both of these services aim to do the same thing, but they do them in totally different ways.

Placecast is offering a new service called ShopAlerts. It is an opt-in service that allows retailers to send text messages to consumers with location based discounts and deals, depending on the consumers’ location. For example, a grocery store may want to send people located within 5 miles of their store grocery coupons, or a shoe store located in a mall might wish to send everyone who is in the mall a message with their latest shoe discounts. Of course, these consumers must have previously opted in to the ShopAlerts service.

Shopkick, on the other hand, is a mobile app, which is currently available on the iTunes App Store. Shopkick rewards it’s users for checking into certain stores, by issuing kickbucks. Kickbucks are issued for simply walking into a store, and also for scanning products. They can be redeemed for gift cards, iPads, music downloads, donations to causes, etc. The app will also provide the users with the latest coupons available in that store. The app is available nationwide, but kickbucks are currently only being issued in 4 major markets: New York, Los Angeles, San Francisco and Chicago. It will be available on Android based phones later this year.

Here is a video demo explaining how Placecast’s ShopAlerts works.

These are just 2 of the latest location based shopping services available. There are more out there, and we should expect to see even more emerge in the near future.