Everything eventually ends up on the web, so you should be careful about what you claim as true.
Daya Baran wrote about false claims by Mint.com and Intuit's retort in Intuit Accuses Mint Of False Claims. Apparently, Mint claims that it has gone from 3,000 new users a day to 850,000 users in a matter of months. I particularly like this: after Baran challanged a senior exec with "presented information that was false," the exec said, "Well we are a startup you know..." as if that excused it.
Here's something fun. Your sales team has asked you for competitive positioning. And maybe you created an exhaustive point-by-point comparison of your product versus the competitor. Mint.com's competitive comparison is this:
That's all? Yup, that's all.
Mint.com is saying, "We're better because we say so. You know, just believe us. Really. (please)."
In years past, we had watchdog groups that would verify vendor claims. Often you'd see the industry analysts weighing in. Nowadays every blogger is a watch group. In IMDB's discussion groups, you'll see members calling out items obviously planted by PR firms. Items get reposted on Facebook with an editorial. Bloggers complain about--or laugh about--vendor claims on their sites. You can no longer assume that what you write for your sales people or for individual customers will stay "inside."
Assume that whatever you claim will be published. Can you back it up? Can your claim hold up under public scrutiny?