In terms of market share, Observer is clearly lagging behind, losing to VisitorVille in all segments.
VisitorVille has better usage coverage in more websites categories. Including E-commerce & Shopping, Health, Arts & Entertainment, Heavy Industry & Engineering and one other category.
Observer hasn't got a lead over VisitorVille in any websites category.
VisitorVille is leading in most countries, including United States, United Kingdom, Canada and France.
Observer is leading in Russia.