Potential future enhancement (watchlist)

I was thinking about a feature that could be useful for me, and hopefully others.  The ability to be notified when a user adds a specific card to their tradelist (or even wishlist).  For example, I have been looking for a Doubling Season for a few months now and seem to have exhausted my resources on this site.  I don't mind waiting a few more months before I finally break down and buy it from eBay or wherever but I would rather trade for the card if I can. 

So, it would be helpful to have a service that informs me whenever a user adds this card to their tradelist so I can see if we can configure a trade that both parties agree upon.  My only alternative is to randomly check back on the list of people trading the card and go through each one of them again and again to find a trade.  This takes a fair amount of time to do as some cards are on 50+ tradelists.

This may not be the right solution and I certainly won't cry if a notification system isn't implemented.  My true issue is the two-fold problem of learning about a desired card being recently added to a tradelist and figuring out whose tradelist it's on without just going through all of them every time.  Something as simple as an indicator on the card page showing that the card was recently added to the tradelist or that I haven't personally seen this tradelist through this card page before might be a suitable alternative.

No huge rush but food for thought nonetheless!