It is not my intent to be rude, so I apologize to readers if this comment is deemed as such. At this point, I shall refrain from further comment of your posts directed at me, in this thread. No offense, these comments have crossed my threshold of courtesy. My concerns are not arguments or opinions; your words, not mine. My concerns pertain to product placement in bookstores. I think this is germane to the OP's query.
I really, really do not care if you reply to me.
People spouting nonsense on subjects which they know next to nothing about is one of my pet peeves. People spouting JUDGEMENTAL nonsense on subjects which they know next to nothing about (and yes, your little snide remark about "parents who care" was VERY judgy and offensive) basically makes me want to hipposlam the crap out of them. Ignore me if you will, but I'm going to keep calling out posts I find nonsensical.
To recap:
1. You don't read MG. Sorry, but "early HP books" followed by scanning the blurbs of MG doesn't mean you "read" MG. Again, as I said, that would be like someone who's read three GoT books saying they "read adult".
2. Um, actually, that is all. If you don't read the age category, you don't get to have an opinion on how it's sold, what is being sold, and who gets to read it. You just don't.
ETA: I see you're still digging your heels about book length...
Although I think some of this derailed the topic, I still believe content and book length are legitimate topics to the OP's query.
Book length are legitimate topics, but this:
434 pages is a bit much for kids.
And this:
If books go 300 pages for 80,000 words (approximate average), and 50,000 words is the upper limit of MG, I think 434 pages (for MG readers) is a bit excessive. This might be 120,000 words. Granted, Mull is a well-established writer, and he is afforded the extra length based on reputation, but is something this long not more geared toward YA (and allow other MG writers space for their books on bookshelves)?
Do you think the majority of MG readers will go for something 434 pages or 270-325? I know what my nephew would choose (he is 12). This is an opinion question. For me, I think 434 pages is daunting for young readers, in general.
Are just plain wrong.
Philip Pullman's NORTHERN LIGHTS/THE GOLDEN COMPASS: 416 pages,
112,815 words
Cornelia Funke's INKHEART: 146,809 words
ERAGON:
157,220 words
THE BOOK THIEF: 118,933 words
THE AMULET OF SAMARKAND: 462 pages, 140,910 words
All of them are best-sellers I can think of just off the top of my head. It's not a question of opinion. Objectively, and I'm saying this the nicest way I can, you're just wrong. MG books' word count range wildly depending on genre and setting. You'll have books as short as 40,000 words and books over 140,000 words, and both can appeal to many, many kids.