I'm with Zain on this, I built a fair portion of my plastics collection at a very good price by hunting for ebay auctions that didn't get much attention, as they weren't all just listed here. Now they are, any ability people have to put in that effort themselves is pointless, as everyone can just check this topic for auctions and push up the price...
As selfish as it may sound to complain about someone making things easier for people and trying to do the right thing (which I understand and appreciate - the meaning of actions is very important), the state of the market for plastics and HMS at the moment is just disgusting (for example, prices for usable/decent condition V2's have risen from $15-$25 to $40 at the bare minimum over the last 6-8 months alone!), and the inflation caused by this kind of publicity is far more detrimental to plastics and collectors than the service is good for them, so overall it really isn't doing a good thing at all.
If sellers on here want to publicise their own auctions, then fine by me, that's a benefit of being a member of this community - more attention etc. By providing that same publicity to people outside the community, you decrease the value/incentive for sellers to be members here.
Those people that don't "have time" to search for auctions, IMO, evidently don't want them as much as those that do, so really it only benefits the lazy rather than those who would put in the effort themselves...
So, don't get me wrong, I appreciate that the people doing this have good intentions, but it really only hurts buyers, both players and collectors, and sellers are plenty capable of advertising themselves if they want to do so, so it removes the advantage of those sellers who put in that effort.