This article was somewhat interesting, but I have to wonder about whether building your own cluster at home would be more cost-effective (considering paying for

This article was somewhat interesting, but I have to wonder about whether building your own cluster at home would be more cost-effective (considering paying for hardware replacement, electricity, etc.) that just using Amazon S3/EC2. Also, if I was one of the author's prospective customers, I would be more likely to put my trust in Amazon than some guy with 3 computers in his basement.