When you write for your customers, you'd rather address them directly in your site copy, instead of speaking about the product, vague benefits or even your company.
Actually, this is all pretty simple. People are only interested in them - even when they are seemingly interested in others. Oh wait. Let's put it this way: you are only interested in yourself - even when you are seemingly interested in others.
Notice the difference?
Direct address - that's what some linguistic geeks tend to call it - is when you speak to a person directly. It naturally prompts the person to pay attention to what you are saying. If you say something important, it makes sure you are heard.
Write for a single person
If you write for no one in particular - for your "average customer", you'd rather be clearly knowing who you write for. The first step of knowing that is to learn who your customers are. The next one is to imagining as if you write for a single, specific person.
Sometimes, you may not have someone specific, in which case, a persona will do. When you don't have one, you can write for your best customer. Why not for an average one? Because you'll want to get the best business you can get without trying to appeal to everyone with your single piece of text.
The more detailed your picture of your best customer is, the more interesting, intricate and fascinating your copy will be. Obviously, the more appealing and useful it will be for your customers.
Speak about the important
Tell the most important things to your customers straight away. Don't pollute the screen with ramblings, excessive comments or anything not related to the target of the copy/text/article. This should keep your readers interested and motivated enough to stick to the end.
Often, this means speaking honestly, even if it can hurt you in one way or another. But speaking sincerely with your potential customers will win trust and, hopefully, admiration among your customers, which is high valuable.
In essence, you need to know and remember who you write for. Apart from knowing the needs of your customers and how to format the text, you need to make sure your message gets through and evokes a reaction, which is beneficial to the customer and desired by you.