You have to search a lot to find what is most likely to work for your web site. Once you get an understanding for each type of advertising then you can put it to work.

Website directories: Helpful for one way links to your website to increase link popularity. Do not expect a lot of clicks.

Free Classified ads: Expect what you pay for. Nothing!

Safe lists: Stay away!

Opt in email lists: Terrific! But you need traffic to build your list of opt-in subscribers…

Free Banner exchanges: You need traffic to get traffic from banner ads! In general you’ll earn one banner impression for every two you display on your page. Try banner campaigns in combination with a pop under campaign. Send that cheap traffic to a web page with original content and some banners from 2-6 free banner exchanges. Be careful: Do not create a banner “farm”! The banner exchanges will suspend your account.

If you buy banner ads on topic related websites, expect a click trough rate of 0.5%-1.5%

Search engine optimisation: A must! But have in mind that it’s a long-term strategy, costing thousands of dollars (unless you know how to do it yourself) but results are not guaranteed…

Cost-per-click text advertising: The best source of traffic, but costing from $0.10 to as much as several dollars per visitor! Even if you have keywords for $0.10, it’s almost impossible to get thousands of visitors every month using only this method.

Writing and distributing articles: Articles can become viral and drive qualified traffic to your website. Include a resource box at the end of your article that features a link back to your site.

Buying ezine ads: Because these ads are targeted, you will see traffic. Be sure to measure the effectiveness of your ad and your cost per visitor!

Pop Under advertising campaigns: Cheap, but you have to know how to properly set-up a pop under campaign. Read this article for some tips for a successful advertisement:
http://www.cnetcs.com/tips.htm
A well-designed pop under campaign can bring lots of cheap visitors, but most advertisers send the visitors to a page that is not especially designed to convert the visitors into customers or subscribers.

PopIn (layer) ads: A good option: Cheap and effective. PopIn ads receive a click trough rate of 1.0% - 2.0% (some popin layer ads receive a CTR of up to 5%).

And one last thing: The industry visitor to customer conversion rate is about 1.0% - 2.0% only if everything else – web design, sales copy, product, prices, etc – is perfect!

That means that you will need 10,000 ad exposures to get one hundred TARGETED visitors (1.0% click trough rate), to convert one of them to a customer (1.0% conversion rate)!

If you make any profits, your web site is a winner! Just buy more ad exposures to make more profits!