Hi,
I have some maybe strange question. I see usually promoting a free lead is easier to do than a sales lead (maybe i'm wrong).
But if it is "harder" (again my assumption), how long does your ad need to be alive to be able to get the lead?
The problem i see is, due the my background in seo, unless someone searches for the specific kw like "golf lesson", sometimes even a targeted traffic might not react the same. Fb for example, they were just casually browsing for stuff, when they see "free" it's a yes. But when they see "paid", they might be interested, browse and contemplate, search for a free alternative instead.
And like my original question, do they need to see your ad over a period of time before they decide to buy? Do you run paid lead campaign with better success than free lead?
Low barrier-to-conversion points are invariably easier to use than those that require whipping out a CC or making a financial commitment, so most affiliates go for SOI/DOI-like offers first.
Whether pay-per-sale or pay-per-lead are more profitable can only be answered by testing.
As for questions like "how long do people need to see my ad for before buying" - again, this kind of question is not something you will get an answer to without testing, and it may not be the case that people are more likely to buy just because they see your ad multiple times...