While writing the offer, sales letter or any other communication material to the customer, you must be specific about what is the next step you want your customers to take.
For example if you are writing copy for newly launched product say Washing Machine, you must include advice what is the next step you want your customers to take
In above case the next step can be
1) Visiting the stores where customer can get this item and launch offer if any ( There must be an offer with Ad)
2) Asking customer to download the application of company from where they can get the product directly from company
3) If this advertisement has coupon code, where he should approach or if it is online how he should approach to get the benefit of coupon.
The father of advertising Claude Hopkins has written in his book that the single objective of advertising should be to generate the #sales not anything else.