This site labels its 6-bottle package specifically as "Most Popular" — worth understanding what that label is, and isn't, backed by.
This label appears directly on the pricing card without a linked, independently verifiable purchasing-data source in the materials reviewed — worth treating it as brand-stated context rather than an audited statistic.
Given the 6-bottle package carries the lowest per-bottle price and free shipping, a stated preference for that tier is a plausible outcome of the pricing structure, worth reading alongside — not as separate proof.