Back-to-school sales are starting at many retailers across America, and a recent survey by installment payment specialist Splitit found that four categories of products -- clothing and shoes, bags, stationery, and electronics -- topped those shopping lists.

Chart showing planned back-to-school purchases by category

Data source: Splitit. Chart by author.

The rush to buy new clothes should benefit apparel retailers that resonate with younger shoppers. Piper Jaffray's latest "Taking Stock with Teens" survey, which polled 8,000 respondents about their top brands, ranked Nike (NKE -0.84%), American Eagle Outfitters (AEO -1.63%), Adidas (ADDYY -1.38%), Forever 21, and Abercrombie & Fitch's (ANF -2.49%) Hollister as their five favorite brands.

Nike and Adidas both reported robust sales growth in North America in their latest quarters, thanks to strong demand for their new shoes and apparel. American Eagle continues to lock in younger shoppers with its namesake jeans and Aerie products, and Hollister's growth stayed consistently positive in recent quarters as it launched fresh products and social media engagement campaigns.

Those retailers might enjoy a back-to-school boost, but Splitit also found that 82% of shoppers planned to spend less than $500 on all their purchases. This indicates that competition for those dollars could be fierce, and weaker retailers could be left out in the cold.