A) Do you define "marginal" as "one in a million"? ;P
B) The only reason I opted for "# requests" instead of "# objects" is because it let me put a hard figure on "number of people dissatisfied if you have a one in a million error rate". Let's say you are doing 4 billion image requests per hour (the time scale is actually irrelevant): then at a 0.0001% error rate (which is what I get from S3) then 4,000 users per hour are getting an error.
C) ... you aren't doing S3 static web hosting if you are keeping access logs, as the only people who know about the request are the user's web browser and the server. You can attempt to detect the error in JavaScript on the client, but you can't keep an access log. If you are logging requests made by your server, then the error rate is irrelevant as you can just retry the operation.
B) The only reason I opted for "# requests" instead of "# objects" is because it let me put a hard figure on "number of people dissatisfied if you have a one in a million error rate". Let's say you are doing 4 billion image requests per hour (the time scale is actually irrelevant): then at a 0.0001% error rate (which is what I get from S3) then 4,000 users per hour are getting an error.
C) ... you aren't doing S3 static web hosting if you are keeping access logs, as the only people who know about the request are the user's web browser and the server. You can attempt to detect the error in JavaScript on the client, but you can't keep an access log. If you are logging requests made by your server, then the error rate is irrelevant as you can just retry the operation.