If a customer gives negative feedback about a seller it is normal for
the seller to _automatically_ give negative feedback about the
customer. As a result few customers who are dissatisfied bother to leave
any feedback at all. A 99.8% positive feedback may exclude the thousands
of dissatisfied customers.

I wouldn't say that. Although many buyers would not leave negative feedback
and the percentages are, therefore, exagerated, I still think that is a
correlation between seller quality and their feedback rating.

Basically, 99.8% is good. Anything below 98% makes you think.

Christian.