YP, formerly known as the Yellow Pages, is partnering with YELP to "enhance its customers' business listings on Yelp," and to add the local reviews leader's site and apps to its local ad network. The tie-up also gives Yelp unspecified "additional means to access local businesses through YP."
Though its print business is a declining cash cow, YP also owns a popular site (YP.com) and apps that provide access to local listings, and an ad network that supports 300+ Web/mobile properties. Publisher partners include Yahoo, AOL, and Pandora.
eMarketer estimates YP will have a 1.6% share of global mobile ad spend in 2014, though that's down from 2.1% in 2013.
Joining YP's local ad network (and thus leveraging its salesforce) could help keep a lid on Yelp's sky-high sales spend. Sales/marketing expenses equaled 52% of Yelp's revenue in Q4.