Testimonials
Demonstrate your effectiveness to potential customers by providing positive feedback that you’ve received from current ones. Reinforce the fact that you are trustworthy, reliable, and get the job done correctly. You should include a minimum of four. If you don’t already have any, request them from happy customers. Explain that they can benefit by including a link to their own website!
Portfolio / Customer List
Offer snapshots (literally and figuratively) of successful projects or the names of client companies. If possible, include a small photo or the logo of each client. Link to client websites and include contact information if they agree.
Comparison to competitors
Compare your product side by side with one or more competitors to persuade visitors to choose yours. A checklist format works well to lead people to the right conclusion. After a head to head comparison, you can add supplementary information such as product history, applications for use and any relevant statistics.
You can even tout your own website as providing better customer support.
Tutorials
Provide tutorials or step-by-step guides to illustrate how the customer can easily use and benefit from your product/service. This information can be more focused than general articles which offer objective advice. Take visitors by the hand and carefully walk them through the steps to use what you’re selling. The longer you keep them at your site, the better chance of a sale.