I would love to see you get this off the ground. I think it would be in alot of the Dapps interest to use the delegation function to send small portions to a marketing fund. A lot of business models (most notably franchise systems) work like that, and you could look at it as the Dapps are the franchisee's of STEEM and a pooled marketing fund would benefit all.

The hardest part is cutting through with a short concise advert. The STEEM ecosystem is quite complex, designing ads that will bring people in can be done, but keeping newcomers is much harder.

#dynamicmarketing is a fabulous initiative, and I wish you all the best with it.