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!