FY Ended December 31, in millions except percentage
| 2019 | 2020 | YoY
---------------|--------|--------|-------
revenue | $184 | $294 | 60%
gross profit | $95 | $155 | 63%
op ex | $143 | $221 | 55%
net (loss) | $(47) | $(67) | (43)%
(loss) ex SBC | $(31) | $(50) | (61)%
free cash flow | $(31) | $(27) | 15%
total users | 46 | 77 | 67%
net retention | 106% | 114% | --