That's just one of the many points that you have to get right to get a Freemium business working. Summing up Vimeo's success to just that one point (the fact that they, basically, advertise the benefits of their premium product in a tangible, omnipresent fashion) is really a gross over-simplification.
Totally agree, it was not meant as total reduction to that point, though I now can see how the title reads that way...
In that case, as "one thing that Vimeo did really right", yes, that works :-)