There are a lot (nine) imprints under the Perseus umbrella:
Avalon Travel
Basic Books
Basic Civitas
Da Capo Press
Da Capo Lifelong Books
PublicAffairs
Running Press
Seal Press
Westview Press
It also has partnerships with:
The Economist
The Nation Institute
Participant Media
The Weinstein Company
A couple of (not necessarily the best ones) news articles about this:
The Bookseller.
Publishers Weekly.