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It sounds better than the rainbow fairy thing, anyway.
Well, as for that...
http://www.workingpartnersltd.co.uk/stories/Same ghostwriting shop.
Strangely enough my AS DS9 loves their series (the dreaded Fairies, the dino ones... and just got hooked on Warriors last week, after bouncing off the first book last year -- too many pages, too small print). I think it is because they are so very predictable, and yes he was able to articulate that he liked not to be stressed out worrying about things turning out OK in the end. He hates scary stories.
It seems like most fiction (and the longer the worse) triggers anxiety in him, especially since a lot of the classics tend to have more unpredictable plot lines, and he hasn't learned to trust in the Disney ending. These cookie cutter series are soothing. He gulped the first book (I sneaked it in on a brand new Kindle formatted to Magic Tree House text density) in less than 4 days last week, and polished off the second one in paperback in 4 days.
Oh, and when I discussed his latest interest with our librarian she said she only has the first three in her collection. They are too long and too hard (reading level about one grade above Percy Jackson) for their targeted maturity level, and she has very few kids who get hooked.
Apparently there are similar issues with the Rainbow Fairies books, and it is true that while they are short and (very, very, very) repetitive the actual AR levels range from mid 3s to low 5s. Quite a few of the fairies books are tagged as NC on the lexile website, which might explain their popularity with gifted kids ("the NC code is applied to books that have a Lexile measure markedly higher than is typical for the publisher's intended audience or designated developmental level of the book [... and] is useful when matching high-ability readers with a book that's still at an appropriate developmental level").
If you have an addict on your hands I suggest library + Friends of the Library used book sales.