No doubt advertising affects language. Where would we be without the free gift, new and improved, or supersize? (Perhaps writing more grammatically and eating more healthily...) In yet another attempt to reduce English to features and selling points, advertisers often use luxuriant to describe their products or services:

Problem is luxuriant means lush growth; thick and rich. As in a luxuriant growth of leaves in the spring. What those advertisers really want is luxurious, as in self-indulgent; comfort, elegance, or enjoyment in the extreme:

As a society, we tolerate a lot of bent or outright broken language rules in advertising. We tune a lot of it out, anyway. But the careful writer should not emulate advertising-speak and should be wary of copying its word usage. Using luxuriant for luxurious is very much considered an error and is to be avoided.