As I’m sure you’re aware, there are 4 toll-free prefixes – 800, 888, 877 and 866.

Although the “800″ prefix has been around for over 40 years, its next oldest sibling, “888″ is only 13 years old. The “877″ prefix came about 11 years ago, while the youngest “866″ has only been in use for 9 years.

Does the longer legacy of the “800″ prefix result in higher conversions when tested against the newer toll-free prefixes?

See which “800″ prefix yields the highest conversion rate in this search marketing industry study performed by Engine Ready.

conversion rates, Landing Page Optimization