Yes, 30 minutes of work is probably just enough to figure out what the business does, not how to market it. I wonder if this all is just an intro offer, trying to sell you real consulting services. I remember reading somewhere about a consultant (not in marketing IIRC), who would give the first hour for free, the next hour at $1, then $2, and so on. The idea was that the work early on is not as valuable to the client, and bigger projects should pay a higher rate. Never tried this myself, but I think that's a neat idea.