An ad will be paid attention to only if readers are given reason to expect that if they continue on, they will learn something of value. The reward that the ad offers can be explicit or implicit, and can even be stated negatively, in the form of a warning of a possible loss. The promise should be specific. Sometimes, a description of the product's design or operating characteristics will be enough to support the claim. Comparisons with competition can be convincing.
Case histories make the reward appear attainable.
A layout should not call attention to itself. It should be a frame within which the various components are arranged. First, the terms should be the terms of the reader's business, not the advertiser's business. This is a principle that shouldn't need to be stated, but the fact is that typography is the least understood part of our business. Text type should be no smaller than 9 point.