FastSpring is leading in Top 100K Sites and Top 1M Sites.
FastSpring has better usage coverage in more websites categories. Including Computer & Electronics, Software, Arts & Entertainment, Internet & Telecom and 100 other categories.
IAI Shop is leading in Shopping, Business & Industry, Clothing, Sports and 50 other categories.
FastSpring is leading in most countries, including United States, India, United Kingdom, Germany and 101 other countries.
IAI Shop is leading in Poland, Lithuania, Latvia, Kyrgyzstan and one other country.