The last two weeks in August generated a notable upswing in conversion rates for online retailers that focus on back-to-school shopping.

Marketing analytics firm Jumpshot analyzed conversion rates and top products on 10 e-commerce sites that sell a large share of school supplies between June 1-Aug. 31, including Wal-Mart Stores Inc.’s Walmart.com, No. 3 in the Internet Retailer 2017 Top 1000;, Target Corp.’s Target.com (No. 20); Amazon.com Inc.’s Amazon.com (No. 1); Staples Inc.’s Staples.com (No. 5); Office Depot Inc.’s OfficeDepot.com (No. 13); Follett Higher Education’s Bkstr.com (No. 80); Scholastic Inc.’s Scholastic.com (No. 94).; eBags Inc.’s eBags.com (No. 155), Poppin’s Poppin.com (No. 476); and Discount School Supply’s DiscountSchoolSupply.com. Jumpshot’s analysis is based on its analysis of more than 160 billion monthly clicks made by 100 million consumers.

Follett, at its site Bkstr.com, had the biggest jump in its average conversion rate, month over month, doubling it to 11.3% in August from 5.6% in July, according to Jumpshot.

Seven of the 10 sites increased their month-over-month conversion rate (August compared with July), and the average increase was 25%. Of the mass merchants, Target increased its conversion the most month over month, by 16%, compared with 12% for Walmart.com.

Here is the percent change in conversion rate in August over July:

Here is how the retailers fared each week:

While Amazon may not have had a big increase in its conversion rate, back-to-school shoppers still bought plenty on Amazon.com as well as other mass merchants’ websites.

The top-selling school supplies on Amazon and Walmart were more “traditional” supplies, such as pencils, crayons and glue sticks, while Staples.com sold a lot of its own brand of paper.

Here are the top five school-supply products sold on each websites between June 1-Aug. 31.

In an ongoing effort to understand the most vital business strategies of merchants that sell online, Internet Retailer is taking a deep dive on conversion rate. Help us improve our estimates and category benchmarks by answering the two questions below.