It changes dramatically depending on when you check. Last night the place was sapped dry, but this morning I saw a shitton of people and I made a ton of card trades.
Really nice system/website. I drop a handful of rares/uncommons/commons/dupes and get fake currency to use on player cards that I do care about.
Wish I had more time this morning before my train to spend with it, I could probably have just about filled my compendium minus a few holes.
Combination of DOTA2 warehouse and that card matching site that's been linked here. Not to mention some persistence. Dota2 WH selection varies from min to min so check back every once in awhile. I notice the selection is better during the day rather than later at night.. Also, don't be afraid of buying up cards you have dupes for. Just use the dota card trading site to match you up. I've picked up and traded Yamateh like 6 different times for different cards I needed. I'd imagine someone like Dendi would be easy to trade for cards you need as well.
Thanks guys, will check it out. Sure beats trying to grind out matches in the compendium matchmaking!