I would start with rewarding administrators with payment (akin to youtube, somewhat proportionally to views -- this creates a strong incentive towards fidelity), revamp post priority algorithms, and add some basic functionality that you need to install an add on (!), RES, to get (what other top 100 website needs this?).
If this happened, Internet would explode from all the rage.
I'm aware it was invested in at a 1/2 billion valuation, and good luck to them, but I stand by my analysis.
Reddit is growing and would continue to grow really quickly. There's no competition in sight. Owning the discussion backbone of the internet is massively valuable, comparable at least to WhatsApp I'd say.
Can it die out due to massive exodus? Sure, but something similar will replace it. And for each iteration (slashdot,digg,etc), those websites have become larger and more consolidated. It's fair to assume at some point it will reach long term stability (particularly if it's properly managed).
As far as reddit growing, is the plan to lose money on each pv but make it up in volume?
Even stack overflow seems to have trouble monetizing, and that's both brand safe and targeted to a valuable audience.