In point of fact, there is only one specific and verifiable reason that these five authors and their books made the Hugo Best Novel ballot this year: that out of the 639 ballots cast in the category by members of last year’s Worldcon and this year’s Worldcon, these were the five that garnered the most votes. I suspect that if you were to ask the people who cast those 639 ballots why they chose the books they chose, the answer would not be because they were influenced by the Internet, or because the author made a bestseller list, or because the publisher had it as a lead title, or because the author had a snazzy goatee or whatever. The answer would be because the voter read that book, and liked it enough to say that it was one of the best science fiction novels they read this year.
Next year, when I plan on becoming a member so I can vote (even though there is no chance I’ll be able to make it to that Worldcon – I just want to be a larger part of the conversation), I’ll have my say. My ballot may not line up with the majority. Had I been able to cast a ballot this year, it probably wouldn’t have looked anything like what the final nomination is now. But the final ballot would be representational. Given the relatively few number of voters, a small handful of extra votes could change the look of the ballot. I would have voted for, say, Ink and Steel not because I like Elizabeth Bear’s Internet Presence or because from all reports she is a decent person to be around or because she was gracious and friendly when I (briefly) met her at a con. I would have voted for Ink and Steel not for any of those reasons, but because I think it is one of the best novels published in 2008. Period.
And yes, Scalzi's title did make me think of Shadow Unit