Ceros is leading in Top 100K Sites and Top 1M Sites.
Ceros has better usage coverage in more websites categories. Including Business & Industry, Arts & Entertainment, Shopping, Finance and 75 other categories.
ReadZ hasn't got a lead over Ceros in any websites category.
Ceros is leading in most countries, including United States, United Kingdom, South Africa, Spain and 38 other countries.
ReadZ is leading in Bahrain and Belarus.