Sir Martin Sorrell, CEO of advertising giant WPP Group, told CNBC that the ad market might be improving then again not. He pointed to Disney which reported earnings and said advertising rates were up 20 percent. Sorrell said that strength is broad-based.

Sorrell said the recession was the worst he had experienced in his decades of business. He said the recovery will be a “slog,” especially when it comes to Western Europe.

Sorrell says the uncertainty was due to two factors: questions about the economy and questions about the policies to come from Washington.

Last week when Cisco CEO John Chambers also described the lookout as uncertainty after Cisco reported earnings.