Personally, I see what you mean but I feel as though that shouldn't be much of a concern.
I feel like the marketing/branding efforts should be focused on the primary defining feature: the marketplace

Thus it should be seen as more of a marketplace with its own coin as opposed to a coin with its own marketplace.

The sling 'coin' itself is nothing innovative, but obviously the market feature is.
Sling is bleeding edge and has the advantage of being first in the 'decentralized market' market.
As such, I think sling should be looking to capture as much marketshare as possible before others have the opportunity to copy its underlying technology.

And I feel the best way to do so again is to keep the focus on the marketplace and getting people to use the market which indirectly gets them to use the coin