The Whiskey Rebellion
Besides being polite this letter provides two remedies that are unusual, and I think there might be a potential third that would make these cases much less contentious.First off, it doesn't demand a removal of the book for sale, but merely requests that the next printing have a different cover.  That's a huge step forward, and since the need here is to protect the trademark ability of the brand, outrageous demands really aren't' called for.  Offering to pay for the cost of changing it if they are willing to do it earlier, is also a generous remedy that protects the brand.   The violator doesn't lose money, and the act of paying for the remedy is an act of protection.I wonder if there isn't a third remedy in cases like this, where it isn't flagrant violations: That being licensing the brand.Certainly trademarks are licensed all the time- coca-cola licensed clothing is a good example.  So, someone using your trademark under license doesn't undermine the ability to protect the mark.Thus they could have offered to license the mark (as a third possibility) for a reasonable fee.  The fee would have to be industry standard (e.g.: "You can use it for $1" would undermine their ability to protect the brand) but I imagine for mildly infringing or only partially infringing situations like this the remedy is probably not too high.Not that the publisher of this book would likely want to take them up on it, but maybe given the books content in some cases that might be preferable-- where the infringement on the brand has positive economic value for the book, and everyone makes out ok.The trademark is protected, and the publisher makes a bit more money by being able to use this design than they would if they had to do something completely different.Further, this activity- of issuing licenses- shows diligence of protecting the mark which enhances its trademark ability.  You might not know all the violators of your trademark, but it is the failure to defend the mark that can cause you to lose it.  A license is obviously not a failure to defend the mark, and so it helps bolster the mark. (This is what it would seem to me, but I'm not a lawyer.)Yet I've never seen someone offer to license the trademark to a violator.