If you are truly serious about making a success out of your business in the long run then there are several factors that if applied correctly and efficiently will make your sales explode to stardom in your market area.
Value for money
The reader feels and thinks he or she is getting their moneys worth. This is a vital marketing principle to boosting your sales. If this objective is achieved then you have essentially done all the hard work, convince your prospects that the product you are offering them is worth substantially more than the price your selling it at.
It is also important that you market products within your means (financially); ideally you should have purchased a copy of the product, this is a key marketing principle that will help you when it is time to market the product as you should have familiarised yourself with it. Also, consider offering free gifts with your products (See Marketing Principle 3); make the customer really feel they are really getting their moneys worth.
Unique
Some of the most effective advertisements are those that are original, captivating and distinctive. The more unique and captivating you are able to convey your products, the better the customer response. Creating mailing lists and newsletters is also another key marketing principle of effectively establishing yourself while building up your rapport with customers; it is definitely something you should look to explore.
Relevance
Make sure when you market a product, that you supplement it with a tightly focussed offer. Having an offer that relates specifically to your product is a very effective marketing principle of establishing credibility. Relevance is important; never venture beyond your given niche.
Desirability
Something can be great value for money, but it doesn't necessarily mean I want to buy it nor does it mean a customer would want to buy it. As a result alleviating the desirability of your product is a crucial marketing principle.
As a method you can try enlisting part of your product as a premium which should not be to hard to accomplish with information products. As a marketing principle, concise wording is very important and if used effectively should put your products in a more favourable position.