Tag lines are not slogans, although they could be.  Slogans can serve as tag lines, as in Nike's "Just do it." Tag lines help the advertiser define the service or product beyond its name or the headline on the ad. As you can imagine, they can be hugely important. Today, an ad for a mattress store caught my eye. It is called Sleepy's. Not sure I care for the name, but the tag line "The Mattress Professionals" just didn't do it for me. In fact, Mattress Professionals would be a better name for a store. Sleepy's is a fairly "unprofessional" name. But they want you to think they know what they are talking about. I think professionals is the not best choice...it doesn't match. I guess "Sleep experts" must be taken...that would have been better. Or "we know mattresses."  In any case, to me this illustrates a disparity between a brand name and its brand identity.  You want to keep those separate.

Please keep in mind that I have never been to a Sleepy's store and this is just a commentary on a particular element of a particular ad.

Any thoughts?