PIPL advertise it services as "the most comprehensive people search on the web.” I cannot quite agree with this statement but they are a helpful person search resource to use with other popular ones like 411.com, 411Locate and ZabaSearch.
"Unlike a typical search-engine, PIPL is designed to retrieve information in real-time from the deep web, our robots are set to interact with searchable databases and extract facts, contact details and other relevant information from personal profiles, member directories, scientific publications, court records and numerous other deep-web sources.", reads one of the pages on PIPL.
As of now I am not convinced that PIPL is N1 people search on the Web, but I like their approach and I am sure that if they manage to get access to more "invisible web" databases, they will become more efficient and well known.
Via: Tales from the Terminal Room