Go for it, I've always wanted to see the sps being used more for non-code purposes/marketing. But I would be careful with a lot of the parameters, and what we are selling.
A good point to market steem would be right before the smt launch, and after communities have launched (aka beta.steemit.com is steemit.com) imo.
There will be a lead-in time to get this up and running which likely take it into the timezone between communities and SMT.
Determining what is the best sales message will be part of the discovery process with a chosen agency. It would be interesting to get a professional outsiders view on what Steem has to offer.