From Longman Dictionary of Contemporary Englishsnowball effectsnowball effectif something has a snowball effect, it starts a series of events or changes that all happen because of each other → snowball
Examples from the Corpus
snowball effect• That affects the mock-up, or test, of the windows, and it has a snowball effect on other trades.• All this has a snowball effect on the day's turnover and on the individual dealers' commissions.• A snowball effect is the desired goal. 