What is the best online marketing strategy you found?
breck: In my experience, from best to ok:1. AdWords. AdWords is a no brainer. Find out the average revenue per visitor from AdWords and set your CPC below this. Instant profits(after some trial and error). The great thing about AdWords is you can get visitors and feedback within hours. You can launch a site in a day and get a sample of how well it will work.2. Organic Link Building. This is the creme de le creme. 
2a. Getting a blogger to write about you. New blog posts get picked up in search engines pretty quick, which will improve your SER. Also initial visits from a well read blog can be substantial.
2b. Social news sites(Digg, Reddit, Twitter, etc.). I haven't mastered these yet, but are pretty effective even when you're just starting out. Not only do they drive some traffic, some of them help with SER.
2c. Commenting on blogs. This seems to also drive some initial traffic and improve SER.3. Yahoo Search Marketing and Microsoft AdCenter. Same as AdWords except less traffic. However, often the visitors from these sites will earn you more/sign up more often.4. Viral strategies. Email campaigns, referrals, making silly YouTube clips.5. Main stream media. Gives you a short burst and then improved SER.