What is your source? I thought this seemed odd, so I went to wikipedia.
yeah, cause wiki is the font of all reliable knowledge.
here ya go:
original twilight cover www.wondrousreads.com/2009/02/original-uk-twilight-cover.html
the NYT list is not based on sales, but interest, do try not to get the two confused.
and the point I was making was that the books did not enter public consiousness until 2007 when they suddenly seemed to explode. there are lots of books that are 'bestsellers', can you honestly name them all? do you even know what the bestsellers this week are? because I sure as hell don't.