From the Nielsen Wire:
…Nearly half of American smartphone owners (47%) used shopping apps in June 2012, according to Nielsen. Overall, 45 million smartphone owners used apps in the Shopping/Commerce category, accessing shopping apps 17 times on average during June 2012.
- eBay, Amazon, and Groupon dominate with 60% of all uniques.
- Shopkick somehow keeps users in the app for 3 hours.
- TechCrunch – Nielsen On U.S. Mobile Shopping