[jpulgarin]

The incentive to respond is the content of the email (or the identify of the sender). If I want to "offer" the receiver of the email an added incentive to respond I can say so in the email. "Respond to this email and I will give you $1000."

[rougefeta]

Sometimes, the incentive cannot be monetary, because the recipient is not interested in money. What the recipient may be interested in is an indication whether it is worth investing in a reply.

We had changed "pays" to "helps" at an earlier stage.