In terms of market share, eProof is clearly lagging behind, losing to Marktest in all segments.
Marktest has better usage coverage in more websites categories. Including People & Society, Arts & Entertainment, Music & Audio, Religion & Spirituality and 3 other categories.
eProof is leading in Finance, Accounting and Adult.
eProof is leading in most countries, including United States.
Marktest hasn't got a lead over eProof in any country.