DEX One

Dex One Corporation was an American marketing company providing online, mobile and print search marketing via their DexKnows.com website, print yellow pages directories and pay-per-click ad networks in the U.S.

x One Corporation was formed in February 2010. It was previously the R. H. Donnelley Company, which was founded in 1886 by Reuben H. Donnelley, son of RR Donnelley founder Richard R. Donnelley, as The Chicago Directory Company.

In 1988, Wile E. Coyote and The Road Runner appeared in a commercial for the Donnelly Directory Yellow Pages.