State the biggest benefit offered by your product or service. Provide a quick and easy way to respond. Keep your message brief. Most short ads I develop produce more replies than longer versions of the same ad. For example, one of the most responsive ads I ever developed has only 14 words.
Offer ends soon.
The off-line version of this ad also included a phone number and postal address so prospects had 3 ways to request more information. I used it for classified ads in magazines and printed it on postcards and mailed them to targeted lists. Every version of the ad produced a large number of replies. Many prospects responded out of curiosity. I knew they were part of my targeted market and had a compelling need for what I was offering.