Earlier this month, Cartwright, a new agency bearing the name of former 72andSunny creative lead Keith Cartwright, formed with WPP’s backing and the ability to tap into Grey’s global network.
Legacy Agencies Help Startups Gain Footing in a Slippery Industry
Cartwright, backed by WPP, is the latest example

Holding companies and bigger agencies are partnering with small agencies to create some of the highly notable ads from the last few years.
P&G, Burger King, Clif Bar, WSJ