House flipping increased in popularity and profitability in the Tri-Cities last year. Investors in six of eight local markets had a gross return on investments (ROI) on flips that were well above the national average. Flippers in Sullivan and Greene counties have the highest gross ROI. The report is also an example of how entrepreneurs see, seize and profit from a market opportunity. According to Attom Data Solutions’ Year-End 2017 U.S.