If you've used effective promotion techniques, they'll already be expecting a product that can help them with whatever issue or problem they face.
Your first job when writing sales copy is to catch the viewers attention with a surprising headline that stands out.
Your second job is to create a desire, need, and hunger for the product.
Make them believe that they can't live without your product.
Like stated above, the traffic you are receiving at your page should already be targeted.
That means that they already have some amount of desire or interest in what you're selling.
Since we don't know how much they really want your product, you must increase the visitor's current desire by 500% in order to remove all doubt they may have in purchasing.
Once you have them helpless, you can let them know that what you have to offer is the solution and will give them the relief they need.
Even if your product is simple and non-life-changing, you can do this to some degree when writing sales copy.
This can be done very easily.
First, take note of all the reasons why a person would want your product.
Why will is solve [problem]? What will happen if they don't have your product? Why is [problem] bad? You can literally come up with dozens and dozens of answers to these questions.
When you integrate this while writing your sales copy, make sure you put all of the "bad stuff" together.
For example, if you were criticizing someone, you wouldn't want to say a bunch of negative things to them at once.
It would make them feel terrible as the list of bad things builds up.
Well, that is our intention, however yours should not have a mean tone whatsoever.
Once they feel helpless and needy, be the hero! You are no longer the marketer to them, you are the solution.
When selling online, you never want to be the marketer, so if you can achieve this, you will most likely get the sale.
Master this when writing sales copy and you are sure to see higher conversion rates very soon.