Advertise your game

Let's start with the expensive solutions:

- News paper / TV / Radio advert - Flyers - And any other traditional advertisement solution. You may wonder why you would spend money to advertise your online service on traditional media, well actually believe it or not, that's still where most of the public knowledge come from. Specially if you want to offer a broad service. Don't tell me you never saw some "trivago" or other travel / hotel website advertised on TV! Why do you think they do it? Because it drives public interest. Of course, traditional media are not cheap and may very well be out of reach of any of us. Still it's something to consider on a side "attack". If you can interest journalist enough that they would talk about your tool in a radio program or a TV show, then it's free advert basically ;)

Banners and other Google like adverts:

Paying to have your service appearing on a banner or other payed online advert system can and will drive some traffic to your site. However most service are a "pay per click" system and while you think it's pretty cheap you will see that you will need lot of money to actually attract interested people, by that I mean those which will want at least to try your service and not simply click there and go away. Depending on the service you offer, you may very well end up paying up to 5$ per real interested visitors. Not cheap by any mean! So prepare some good amount and don't simply try 10$ advert as it will most likely 10$ lost.

Forums:

Yes forums are still widely used, but it also depends on the service you want to offer and which forum you can post on. Many forums don't accept advert post, and you may very well get kicked out after trying. So either you don't care and try or you may consider either have your service in a signature of your user and post useful info and therefore indirectly advert. Anyhow forums can still drive traffic if well done.

Twitter / Facebook / Other social:

This is maybe the best free way to advert your service, however it is by itself a science. You cannot simply put your link on some Facebook page and expect it works. You must somehow have a community interested in your service and be ready to try it. So you will need some smart approach to do it or you may very well just upset people if you start spamming with your service.

Online E-Zine:

Beside advert on those site, you may interest the people behind it which needs to write article to post something about your service. This would at the end be a win / win situation as both you and the journal gain something out of it. However don't try this road too quickly, be sure you have something of a good value before approaching a big website as they will not talk twice about the same service, and will most likely not look twice at you if the first time you just had a barely running service.

IRC:

Yes it's an old media, but you may very well come in some chat and ask for people to help you testing or talk about your adventure. It may or may not drive some people to your site but again it should not cost you much.

Referral campaigns:

Your users could actually help you in driving more traffic. How? Well by inviting friends to do so. Beside that if your service is good enough they should start to slowly doing it alone, you could help this by offering goodies if they invite some friends. Could be some online advantage or could be some real one (money, goods or whatever). Beside jumping on this, be careful that some will for sure try to get those advantages without doing anything beside creating pseudo users.

Contests:

Creating a contest can drive people to your site. For example, if your game has a monthly reset, you could offer some real win once in a while and people will most likely want to play just to win the real goods. Of course you should not scam them otherwise you may very well end up loosing all your visitors.