I think this is what alt meant:
* very low fee to create an asset, but it can't be traded on bitshares market yet
* to enable the asset to actively trade on bitshares market, the creator has to pay something like 100 BTS/week
* but to reward the creator, he gets a percentage on all asset transfer/trade fee, so he has a chance to make the maintenance fee back or even make a profit if his asset is popular
* this will reduce the number of spam/low quality assets trading on bitshares market
* the creator still has the option to trade offline, (ie. send me 1 BTS, I send you 100 shares of my asset.)