In terms of market share, ReferLocal is clearly lagging behind, losing to Simple AdServer in all segments.
ReferLocal has better usage coverage in more websites categories. Including Business & Industry, News & Media, Tourism, Travel and 3 other categories.
Simple AdServer is leading in Shopping, Sports, Adult, Autos & Vehicles and 3 other categories.
ReferLocal is leading in most countries, including United States, United Kingdom and France.
Simple AdServer is leading in Hungary.