Another rollup winner is Sysco, the nation's largest food-service distributor, supplying everything from restaurants to hospitals.

FORBES: Which Conglomerators Are the Big Winners?

That was during the dot-bust rollup, and I said it was impossible to do another Oracle.

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But a rollup of a fragmented industry is all about the details.

FORBES: Connect

Fitting together a gaggle of autonomous businesses isn't easy, as Century Business Services, an accounting and consulting rollup, has found out after vacuuming up 135 owner-operated shops.

FORBES: Which Conglomerators Are the Big Winners?

Since the mid-1990s the strategic rollup has been a corporate fad: Large acquirers buy smaller players in fragmented industries, reaching for critical mass, McDonald's-like uniformity and that beloved state of bliss called synergy.

FORBES: Which Conglomerators Are the Big Winners?

The rollup record, though, is mixed.

FORBES: Which Conglomerators Are the Big Winners?