Proper chalking is essential but the biggest problem in my opinion is the residue left over that get in your carpet, table, drink, etc. If you could incorporate a miniature vacuum of sorts into the Chalk-O-Matic (you might want to work on the name a little, perhaps the Shark Auto-Chalker, but it works) that could suck in the dust as it is produced, it could bring a new level of convenience into your product.