Simple advice: if somebody expresses even a slight interest in your product keep calling until you get firm "no - I don't want your product" (preferably not yelling at you). And founder(s) MUST BE doing that 'till company has maybe 5 to 6 employees. Even if founders are not "good in sales". When company is early, there is no "good in sales": it is just if your product solves the problem or not.