Beware too that some advances, while looking like possible acquisition discussions, are nothing more than intelligence gathering. Another reason to heed PG's advice to keep looking ahead while ignoring the hand wavers.
I believe this happened to Justin Kan when he visited Google with Kiko. They just wanted to know his numbers, and then they ended up building the product.
Could you expand on this a bit? It's the first time I read that phrase - it could be because English isn't my first language. What do you mean with 'hand wavers', people complimenting you on your work without making concrete offers / becoming customers?