Hi, regarding affiliate marketing: you need to test until you find a profitable combination of offer an traffic souce. Probably there are differences between the traffic sources. In one you need more money to test in another less. So my question is: in which traffic sources can you test an offer WITH THE LEAST AMOUNT OF MONEY? With “test” I mean that I need to see if it the campaign is/can be profitable or not.
If you are in the make money online or internet marketing niche then Solo ads can be cheap to test campaigns with. Just be careful not to buy traffic from a shady seller. Check their reviews and see if they've been selling ads for a while.