Get someone else to do your selling for you. Quote them.

“Since installing X’s sales management product, we’ve seen a significant increase in orders.”
(A Customer)

A third-party endorsement or reference is the best way to add credibility to promotional materials. Work hard to get a concrete statement like the one above, if you can. If all you can extract from a customer is something bland like:

“X’s sales management product is helping us to manage our sales”

then you’re better off without the endorsement.

Press releases have a grand tradition of the anodyne quotation, serving no purpose other than to massage the egos of the managers involved in the deal. For example:

“We’re delighted to be partnering with X. Our products are a great fit.”

No self-respecting journalist takes any notice of this sort of flimflam. Why not get the managers to say something factual and therefore quotable?

“Our customers can now use X’s product without having to install anything or pay setup fees and that’s a tremendous advantage.”

Finally, only quotations should come in quotation marks. For example: Talking about his new ‘virtual community’, John Blog said: “It’s, like, real”. Don’t use quotation marks just to provide emphasis or make slang respectable. Their purpose is self-defining: to mark a quotation.