Difference between corporation's advertising its' product and what it says on it's website.
The reason there would even be a difference is because these two actions have two different intents and possibly cater to different audiences.
The point of a corporation's advertising is to pique interest in its' product to the widest audiences possible. The way I see it, it's website is just a more focused, real version of it's advertisements - once the advertisements have gotten certain people to check the website, those people care enough about the product and the company that the corporation can be more direct and frank with them.
Both demonstrate professionality.