I am sure this have been discussed somewhere in this forum...if so, please kindly point me there ;-) I am aware there are couple types of traffics such as ppc, media buy, ppv, off-site seo, offline, etc. Some use certain traffics solely for brandings, others to convert offers, etc. I know it depends on too many factors such as landing page, affiliate products, ads, type of niches, etc. Those who have tried many different type of traffics with SIMILAR campaign, please post the type of traffic that converts into highest ROI of expense *AND* time. If you want to keep it a secret, you don't have to explain it in details. Just one word would do like "PPV", "PPC", etc. No theories or opinions please. Just your actual experience.
I'll go first :p