Quote Originally Posted by Chris View Post
Daily uniques aren't immune to those same issues. The same percentage of a whole should be affected and thuse the same margin of error.
You are correct that daily uniques are not immune, but they would be less susceptible to causes like different users using the same computers or different computers sharing the same IP address. There would also be less skew caused by the factors describe above. Notice the key word "less".

They say there are three types of lies: lies, damn lies and statistics. I'd say there is a fourth lie, "uniques".