It can be difficult to blend corporate cultures and turn the next blockbuster merger into a beautiful business marriage, causing many mergers to fail. Companies could avoid all this heart ache before any deal ever gets done by kicking each other's cultural tires, said Bain & Company's Dale Stafford. "Companies actually don't do a particularly good job of assessing culture," he said. "There is so much focus on the nuts and bolts, the accounting and the economics."