Create pages or groups on social media websites. Then there are also going to be groups on gaming in social media sites as well, you could add your link on those pages as well. But post your link only once a month, so that you stay away from facebook radars. Or else you could get banned from facebook. Then also look for forums on gaming, look into those and post your link over there, or you can also latter get a signature and put a key word and set it with a hyper link on it with your website. Then people write blogs on games all the time, you can read those and then you can leave your comment on that and also tell people about your website as well. Link you comment to your website so that web crawlers don't find your post to be spamming. And if it helps even more, type in names of your competitors and well, and give the better points about your website and attract your customers to come to your site instead of your competitors
Go ahead and look into cheathappens discussion forum, join and share your website there, thousand of people lover of games are there you can best promote your website into such places!
The social networking sights are great to use, chat rooms and the like. Go into a room for games on yahoo, my space, AOL, whatever and just go in and tell people about it or post a link. Go through your e-mail contact list and send everyone in it an e-mail about what you have. You just don't have to limit yourself to only gaming chat rooms though. Hit them all. you can also hire experts from SEOclerks who can help you in increasing your ranking, traffic, viewers and in marketing at cheap rates.
There are a lot of arcade sites in the internet already...so you have to think of a way to stand out from the crowd. What I suggest is, 1) Create addictive demo version of the game and let the gamer to play, promote it through Youtube and Gamer community forums/social sites. 2) Do a Press Release, I think it will also help. All the Best, Mate.
Forums won't help. Give good deals and promote your website via advertising. I am myself a gamer and i love deals, Discounts, Bargains, Good Payment options etc. If you are talking about flash gaming websites then add as much multiplayer games as possible
I'm telling you that the most efficient method to promote a gaming portal is by creating flash or html5 games and spread them on as many websites as you can. Set a goal like develop or sponsor 200 good games and publish each of them on 500 websites. In return every website will give you at least 2 visitors per month. The total would be: 200 games x 500 websites x 2 visitors = 200 000 unique visitors per month.