While the technical issues and design of your site are clearly important, I'd suggest that you also be sure to devote copywriting resources as follows:

Sell Don't Tell: Customers are not interested in your point of view on your product. They don't care about all the fascinating features that your team worked so hard to include. What they are interested in is how the product can help improve their lives. This means that your copy should focus on the benefits to them, not on the features which you or your team might be most impressed with yourselves for creating.

Appeal to Emotion!: The most successful copy touches the potential customer personally or emotionally. You want to catch their attention by appealing to their own self-interest and in as dramatic a fashion as is appropriate for the context. In other words, people are self-interested -- so your copy needs to answer how your product or service will make them feel better about themselves. How does this product make my life easier, help me make more money, look better, lose weight, etc.

Headlines are Important: Spend extra time boiling your message down to its key components. Eye-catching headlines are your best chance to catch the eyes of passersby. While colors, font size and placement can all help attract the eye, too, it is the few critical words contained in the headline that ultimately attract clicks. (This is especially true in the plain text "subject" lines of email marketing pieces.)

Call to Action: Even the best writing will fail to help you reach your conversion goals if it does not include a call to action. Determine what action you want the visitor to take before you even start writing. Then be sure to finish your copy by posting a link or offering another specific next step for them to pursue the goal you have driven them toward.

Add Testimonials: Nobody likes to be alone. Especially in the anonymous online world customers appreciate companionship and validation. Collect and post testimonials from other customers to help provide them with the reassurance that they crave. This simple tool will help them to help you reach your conversion goals quicker.