Almost any business can be, but those with limited start up and inventory costs obviously fare better, faster, but sometimes are more difficult to scale as others have suggested. I'd suggest reading Profit First by Mike Michalowicz (his blog and source for the book is at http://www.mikemichalowicz.com/money-strategies/profit-first-money-strategies/) for a way to switch thinking to achieve profitability and positive cash flow first in almost any business.