Scale is a useful concept for understanding advocate influence. Sites like Klout track the online influence of individual users. Online "influence" is frequently inflated because it fails to accommodate a) real world respectability and b) the objectivity of the advocate.
While algorithms are advanced enough to weed out the influence of "paid influence" (i.e. buying social followers) it will always bedevil online statistics. More critical is the fact that an online advocate without a "real-world" reach is usually as useful as their online following--which may or may not consist of high value followers. And it is simply impossible to gauge if they are being paid to post, comment or advocate.
In short, not all online advocates are created equally. That is why you must conduct brand advocacy campaigns through strong connections with respectable anlaysts, editors and opinion makers. We'd rather rather overlook a "Mommy Blogger" who is big in her own little ocean that a true, sometimes even traditiona l Media Maven with real-world respect.