I would start with your own country, and any other countries that you have a good understanding of the culture. It's a big advantage if you understand how people think, interact with each other and do business!
Once you have a good idea of what works in your own culture I would look at the list of most active SFI countries and try to advertise there. The most active countries are listed on the growth tab, and someone has kindly list the current ones for you in a previous answer!
I would also try to advertise in countries that are going through financial difficulties, where many people may have lost their jobs or overtime, or where interest rates have gone up significantly which would mean many people are probably struggling to meet loan payments. In these situations you will find people who have the motivation to start a second income to help pay the bills, or maybe need to build a full time income from scratch. Many of these are 'rich' countries so people are used to larger incomes and want to maintain them if they can. The USA and some European countries fit into that category!
Lastly I would try some of the 'emerging' economies, such as India and Russia, purely because their populations are so large! That gives you huge potential return on investment on any advertising that you do!
I hope you have fun exploring some of the endless possibilities we have with SFI and the globalised business world we live in now!
I would start with your own country, and any other countries that you have a good understanding of the culture. It's a big advantage if you understand how people think, interact with each other and do business!
Once you have a good idea of what works in your own culture I would look at the list of most active SFI countries and try to advertise there. The most active countries are listed on the growth tab, and someone has kindly list the current ones for you in a previous answer!