My best marketing technique is to learn & apply everthing you can in relation to search engine optimization. The problem is, there are so many resources for that, with many different varying opinions. And the reason for THAT is that Google, etc. does not publish any real guide for what you need to know n building your web site.
So you have to study all of this information and then test it for yourself. If your hosting company does not offer a good stats program, I would suggest buying one. And instead of having expectations that you will make a great amount of money, assume you will not, at least in the first 6 months.
Do keyword research – http://inventory.overture.com/d/searchinventory/suggestion/
Type in what you think a potential customer visiting your web site is looking for and go from there in optimizing your pages for the search engines. It is best to start out with a niche word or phrase, as the competition is not as great, and you can test out what works or not.
You cannot have any idea, as far as what traffic will translate into dollars, until you have targeted traffic coming into your site. And as far as targeting words and phrases that place high in natural search, you will need to do link exchanges with other related themed sites, with the anchor text being the name/phrase you are targeting. Make your web site attractive to potential link partners. This means trying to name your link pages something related to your and their themes, such as poker or blackjack, and keep the STATIC links on that page numbered to 25 total or less.
If we (gambling portals) still had any decent PPC advertising available to use, I would suggest using that. But what is left is low traffic, fraud sites. There are niche avenues still available, but if you want any serious gambling traffic, you still have to go through Google, and to a lesser extent MSN search and Yahoo.