Marchex is a hybrid of online advertising services and tech and consumer-focused websites (150,000+!). They have 26MM monthly uniques. Not bad.
They own 93% of the Seattle zip code websites which provides a zip code entry into the Openlist data. They also cover all zip code areas nationally via specific zip code domains and vertical sites.
They also own 300+ locally-focused vertical domains in Seattle such as Seattleinsurance.com. These pages are vertically focused versions of Openlist.
Openlist aggregates reviews from other web publishers to give people a more comprehensive look at a business and they allow merchants to sign up and add data for free. They think they can bring value by summarizing 50 reviews for one business and turning qualitative data into quantitative data to make it easier for readers to understand and use.