How can you use LinkedIn for sales and increase your own credibility? Lots of ways. And let me say right upfront that it's important to do them because your prospects are checking you out too.
The first thing I'd suggest is that you ask your customers to write recommendations for you. Have them write about the results you've helped them achieve and what you or your company was like to work with.
When your prospects see them, they'll be impressed -- especially since most have never written a recommendation for salespeople before.
Another thing you can do is to join -- and participate -- in LinkedIn groups that are populated by your targeted prospect. For example, I've joined a VP of Sales group online. You'll find groups for every profession and a variety of market segments.
Finally, update your status frequently with business relevant topics. Let people know that you're giving a demo. Tell them that you're reading an interesting article & provide a link. Never sell though. That'll kill you!
You have 100% control of your digital image on LinkedIn. By using it wisely, you'll be seen as the invaluable resource that you are!