I would focus on learning to build my own advertising system based on text ads. The idea is that you use small inexpensive text ads to drive leads back to your SFI gateway page. A more advanced version would be to drive the leads back to a small website that you own and build your own list. This would enable you to market SFI to your list as much as you desire. Also, with your own list you can make special offers and better track your results.
If you "bootstrap" your business with $100 per month into a small ad system you'll learn everything you need to know to manage much larger amounts. Building a lead system is the most important skill you can develop!
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I would focus on learning to build my own advertising system based on text ads. The idea is that you use small inexpensive text ads to drive leads back to your SFI gateway page. A more advanced version would be to drive the leads back to a small website that you own and build your own list. This would enable you to market SFI to your list as much as you desire. Also, with your own list you can make special offers and better track your results.