A vital piece of know-how that applies to all marketing everywhere:

Don’t answer all their questions.

If your advertising or website tells them everything there is to know, why should they bother contacting you? You never get a chance to talk to and close a prospect. They either call up ready to buy, or you never hear from them.
Yes, especially a website should have a lot of information on it. But that information is really there only to satisfy three requirements:

1. So they can be reasonably sure what you are offering is what they are looking for.
2. To provide the back-up for your benefits claims (“features and benefits”), and otherwise build credibility.
3. To save time in sales cycles by providing answers to questions you are having to answer over-and-over.

If you tell the prospect TOO much, you are throwing the baby out with the bath water. The baby in this case being a reach – someone contacting you, by phone or email or a reply card or walking into your store.
In short, there is a point where marketing ends off and sales begins.
There are a couple of exceptions:
An online store includes the sales process as well as the marketing process – so you had better leave no question unanswered (other than “just how delighted AM I going to be with my purchase” or “Exactly how am I going to word my letter of endorsement back to the company”).
With retail marketing of products well known to the consumer, there isn’t anything much to tell in your advertising other than your price, that you have the product in stock, your address and hours of operation. In this case, the selling has already been done (the consumer is a loyal user of Blando brand fruit juice, the only question is when and where and how much will they buy).
Otherwise, your marketing is always a careful calculation of what to tell and what not to tell the prospective customer.