In terms of market share, Observer is clearly lagging behind, losing to WebProspector in all segments.
WebProspector has better usage coverage in more websites categories. Including Business & Industry, Internet & Telecom, Marketing & Advertising, Computer & Electronics and 40 other categories.
Observer is leading in People & Society, Web Design, Photography, Travel and 12 other categories.
WebProspector is leading in most countries, including Germany, Austria, France, Netherlands and 12 other countries.
Observer is leading in United States, Russia, United Kingdom, Brazil and 4 other countries.