When you say it yourself (first-party) it’s a claim, when an “independent third-party” says it — it’s a fact. There is no higher credibility than “independent third-party“credibility and in many cases it’s absolutely crucial — because the existing “first-party credibility” is so weak.
This is particularly true for car salespeople, advertising practitioners and members of congress who rank at the bottom in terms of honesty and ethical standards from a December 2014 Gallup Poll: