Technically, this isn't an ebook, and they don't say it is. This is HarperCollins' 'Browse Inside' flash-based widget, which is their answer to Amazon's Look Inside. You're not supposed to download and read elsewhere, you're supposed to be trapped on their site, and as stupid and ridiculous as this sounds to the rest of us, it is what HC intended it to be.
They use the same system across all their sites, including the US and the UK (although you'll have a hard time tracking down examples on the UK site). Their new UK site is truly awful. If you want a laugh, check out the tags on this page:
http://www.harpercollins.co.uk/Conte....aspx?id=38093