As smartphones became the majority in the U.S. in 2012, 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.

Major brands already well-known for online buying are also behind the most-used smartphone shopping apps. In June the eBay and Amazon apps topped the list, attracting 13 million and 12 million unique users, respectively. Likewise, traditional retailers like Target and Walgreens received significant mobile traffic from savvy shoppers looking to find the best deals in their local retail stores.

“Retailers are finding that consumers are willing to use smartphone apps to enhance their shopping experience, and this data shows usage of shopping apps is growing,” said Don Kellogg, Director of Telecom Insights at Nielsen.

Daily deal sites like Groupon and LivingSocial saw more than 10 million Americans using their apps during June 2012. Apps like Shopkick, Out of Milk, and RedLaser rounded out the list of top 10 shopping apps in June, reflecting the unique opportunities for apps to engage shoppers in retail locations.

“As more Americans use their smartphones while shopping and making purchases directly through apps, retailers should consider personalizing their targeted offerings around the needs of individual consumers,” said Kellogg.