Yeah, I hear you. Now in that case, I'd make it extra easy..for instance, when we had a bug and that problem was thrown at us with Chalkboard, we offered another month free(as it's a paid app).

@FollowWithoutContactInfo: CHALKBOARDHQ.com SUCKS, I CANT MAKE A PROJECT

^^ We'd reply: Hey, sorry about that, we had [xyz] happen to us. But can you please shoot me an email at emil@chalkboardhq.com.

Either in that tweet or in the email which we respond, we'd thank them also offering something in return for that. It's not necessary but it definitely provides gorilla value to the customer.