I'm getting organic search traffic for niche keywords, like 'free solitaire online'. http://sudokuisland.com seems to have a decent amount of keywords already, but perhaps you can think of more. Organic search is probably the only way to get traffic at the scale you need for an ad-monetized game.
My plan is to improve the PageRank and DomainRank, and eventually to make the product better (since Google presumably picks up on that through bounce rates, time on site, sharing). So that'd be the general strategy I recommend.
Another metric you can optimize is the number of times a first-time visitor returns, because it acts as a multiplier on your traffic. Say you get 100 organic first-time visitors per day, if each visitor returns 5 times, you'll have 600 total visits per day.
My plan is to improve the PageRank and DomainRank, and eventually to make the product better (since Google presumably picks up on that through bounce rates, time on site, sharing). So that'd be the general strategy I recommend.
Another metric you can optimize is the number of times a first-time visitor returns, because it acts as a multiplier on your traffic. Say you get 100 organic first-time visitors per day, if each visitor returns 5 times, you'll have 600 total visits per day.