Too many people new to business think they can sell to everyone. They buy with emotion and justify with logic. Give them good emotional reasons to buy, then show them why their purchase was a really sensible move. They only care about what your product or service can do for them. They want to know that it will do something to improve their lives in some way - not that it is packed with technology they neither understand nor appreciate.
People hate unexplained acronyms in body text.
Use plain language and keep sentences reasonably short. You don't have to be a multi-national to have a corporate image. Look at how you or your company appears to your customers from their point of view. If you have a high quality product or service, you need to position yourself appropriately in the marketplace using well-designed, high class print and promotional material to project a consistent, congruent image. Study them carefully and angle your copy to match their house style.