There's one participant in particular that benefits largely from the Monero community, and should be in a position to 'give a little back', and that is Poloniex, which has an apparent dramatic increase in popularity and trading activity, in no small part thanks to Monero. Just my 2 cents, but I think that it would be great if they would donate a small % of their Monero trading fees to the development fund.
I also thought about poloniex role in this process but did not come to a proper solution.
there are basically two scenarios:
1.) busoni keeps his place as basically the monopoly of xmr trading - in this situation he should support xmr in the best possible way. I think if he does this position would be self enforcing.
2.) a bigger exchange overtakes his position (btc-e?), in this case he would be worse off.
that said - it could be a marketing idea of an exchange to say it funds the development of xmr