Being a game centered around IAP, the new single-player modes in the last two Hearthstone expansions (Dungeon Run and Monster Hunt) don’t seem to make a lot of sense. You can play those modes indefinitely without a need to pay. So why did Blizzard add these modes to the game?
Well I had a think about it, and the reason is most likely to allow us to try all sorts of cards from the expansion that we wouldn’t otherwise be able to play (unless they came up on the weekly Tavern Brawl). Letting us play with those cards would help us discover cool and powerful cards from the set (if you’re not already aware of them), which should incite us to either buy packs to get those cards (fool’s errand) or use dust to craft them. Eventually we’ll run out of dust though, so it seems like there should be a way to buy dust (aside from packs?)