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, People & Society, Music & Audio and 6 other categories.
Simple AdServer is leading in Computer & Electronics, Shopping, Sports, Adult and 5 other categories.
ReferLocal is leading in most countries, including United States, China and Japan.
Simple AdServer is leading in Hungary and India.