Marktest is leading in Top 10K Sites and Top 100K Sites.
Vizu has better usage coverage in more websites categories. Including Arts & Entertainment, People & Society, Computer & Electronics, Internet & Telecom and 36 other categories.
Marktest is leading in Newspapers.
Vizu is leading in most countries, including United States, Indonesia, Russia, United Kingdom and 18 other countries.
Marktest is leading in Portugal.