As a result, when the buyer was announced, there was a scramble to determine whether Trex would transfer the contract or find a new provider.

"We had to get out to their data center very quickly, hold meetings with their executives and people working on our account, check out their business plan and financials, check references -- all in a tight period of time," she said. "I would have rather had it spread out."

"It's terrible when you don't know who the acquirer will be," agrees Scheuble. "I'd be trying to figure out the likely buyer and creating contingency plans based on what I know."

Talk Early,Talk Often

An outsourcer acquisition brings FUD: fear, uncertainty and doubt. Customers may wonder whether to stick with the buyer or move to a new provider and just where they fit in the new provider's strategy.