If a buyer placed an order and chooses "Link only" the seller will write his own text according to the theme of the link. If they choose "Ad text" The buyer will create their own.
You should create the headline as well as the message. I hope you get a lot of good traffic!
You do have a choice. Most list owners as myself are experts at writing enticing and energetic emails that encourage out list to respond. We know from whence our traffic comes and what they are likely to respond to best in terms of ad copy. I mean to say also that we generated the members to our list by some marketing message in the first instance. Why not let us do the ad copy when we rent the names to you?
Thank you, have an awesome day :)