I'm not commenting on Jack's comment on Twitter's pace of growth. I'm commenting on the your assertion that "Net profit is the biggest determinant of sustainability. Or at least a break even". There are many companies who for many years were not profitable nor breaking even. Many are still running profitable or not today.It's there in black and white out of Jack's own mouth. I am pretty inclined to believe the person who ran the company for years (and my own experience) over some random dude on the internet.