eProof is leading in Top 10K Sites and Top 100K Sites.
Observer has better usage coverage in more websites categories. Including Business & Industry, Arts & Entertainment, Computer & Electronics, Internet & Telecom and 28 other categories.
eProof is leading in News & Media, Accounting and Finance.
Observer is leading in most countries, including Russia, United States, United Kingdom, Brazil and 8 other countries.
eProof hasn't got a lead over Observer in any country.