For $1,000 we can get in front of 120,000 users. Great exposure.
The main problem isn't reaching people.
It's making them subscribe, so that the cost is being recovered.
When AH launched on steam, there were tens of thousands of downloads. Many of them because it was recommened to them because of them playing 'similar' games.
Almost nobody subscribed.
Even the best advertising doesn't help much if the product doesn't appeal to the customer. AH, at least in it's current form, is not the game the world just has been waiting for and does not know it already exists.
(Now waiting for the "steamers are just gamers, we don't want that ilk", "damn millenials/youth of today/instant gratification crowd" comments
)