#14 Gift Card To Down Under
A few years back, an online store had a promotion where whoever spent the most money over a month would get free round-trip airplane tickets to anywhere in the world. My friend found out that you could buy gift certificates on the site. So, he bought a $25 gift certificate and would use it to buy another $25 gift certificate. He repeated this spending pattern and in the end, he ended up spending only $25 for round-trip tickets to Australia.
Credit: BrushGoodDar