Marktest is leading in Top 10K Sites and Top 100K Sites.
w3roi has better usage coverage in more websites categories. Including Internet & Telecom, Business & Industry, Computer & Electronics, Health and 24 other categories.
Marktest is leading in People & Society, Arts & Entertainment, Music & Audio, Religion & Spirituality and one other category.
w3roi is leading in most countries, including United States, China, India, United Kingdom and 5 other countries.
Marktest hasn't got a lead over w3roi in any country.