This topic has been already discussed before so I can only repeat my opinion that I don't believe in this.
Maybe only pinterest give some sense for me also because it is not time consuming (I upload image and link to CGT in few seconds - and wheather it has some impact or not? - I don't know I am more sceptic).
But using common sense - advertising give sense only for big sellers like Hum3d, Squir etc. which can provide huge models portfolio to thier customers.
I don't see any logic that somebody who needs some specific 3D model for his project would for example visit my portfolio with only 100+ models because it is advertised. It is non-sense.
Only thing which gives sense is to constantly upload new 3D models here.