[tarr11]

Most of your "heck yes" people will disappear or forget anything about having that conversation within a few days as well.

Also, discount anyone who has any reason to please you. Their responses are often biased and not helpful towards validation.

[danieltillett]

This is true. They can still be useful if you can interview them in depth to determine why they are saying "heck yes". When doing this make sure to ask them about other services, especially failed ones. This will help you work out if they love your service or are just the type to say yes to everyone.