Members can chose to have their White List not show. It's one of the options in our profile. So reviewer A may have White Lists but chose for them not to show when checked by someone.

I have read some providers here on TER state they don't acknowledge the White list as a reference. Some aren't aware of it. It seems at least that the ones you have consulted pay attention to it.

I'm sure most providers will say that if they use it at all it is just one of the things they consider when being contacted by a prospective client.

I have read some say that indeed quality over quantity is important.

Based on the ability to have the white list not be visible I would say the white list only is not best evidence in reaching the conclusion that one reviewer is more quality than another.

Seems both quality and quantity is to be considered. How much weight is given to each depends on the provider and what is important to her.

Every hobbyest needs to be aware that the qualities that would compel a provider to white list him are important. I'm confident most are. I'm also aware that there are some that are not aware or don't care.

Just seeing a particular provider does not automatically guarantee a whitelist referral.  You have to request it of her.  Some providers do not even give the referrals.  How much they mean to providers is up to them anyway.

Swim