I see what you mean, but I think shortsighted or timid are better terms than greedy. If the paid-for content drove ad revenue above and beyond the creation cost

I see what you mean, but I think shortsighted or timid are better terms than greedy. If the paid-for content drove ad revenue above and beyond the creation cost, they'd actually be MAKING money. They'd need to work out how text tweets don't get subsidized while video does, or figure out the right way to subsidize text. Not that many text tweet contibutors would be worth paying, but not that many video ones would be worth it either.