Usablenet is leading in Top 100K Sites and Top 1M Sites.
Usablenet has better usage coverage in more websites categories. Including Shopping, Business & Industry, Clothing, Home & Garden and 20 other categories.
Zeta Search is leading in Finance, Internet & Telecom, Health, People & Society and 15 other categories.
Usablenet is leading in most countries, including United States, United Kingdom, Spain, Russia and 5 other countries.
Zeta Search is leading in Canada and Greece.