One of the great things about SXSW is the opportunities it provides to challenge your expectations. When I first read about Blake Mycoskie’s keynote address in the schedule I was underwhelmed to say the least. “He’s a shoe salesman? This is gonna suuuuuuuuck,” I thought as I scoured the text for signs that this would be worthy of attending. I had never heard of TOMS shoes and I couldn’t imagine what would compel the SXSW crew to bring in a guy who makes shoes. Still, I had trust that they wouldn’t subject us to Al Bundy without a higher purpose. So I showed up.

I’m glad I did.

It turns out that Blake Mycoskie is no ordinary shoe salesman. He’s a serial entrepreneur who happens to look a lot like McConaughey. He also appeared on the CBS reality TV show The Amazing Race. At this point my skepticism seemed entirely valid. However, his loss on The Amazing Race started a string of events that might change the world for the better.

Worn out from working at his latest (fifth?) start-up, Blake took a vacation to Argentina to soak up the countryside in a way he couldn’t while he was racing across it. He volunteered to hand out shoes to needy children and was instantly hooked by the expression of joy that lit up the kids’ faces when their shoes were placed on their feet.

Mycoskie decided to start a for-profit company — what would incorporate One for One giving into its business model. That means for every single pair of shoes he sold, he would donate another pair to a needy child. No percentages, no after-tax profits, no hedging. TOMS does it straight-up: One for One.

At first blanch, it sounds insane. How could that be sustainable? Wouldn’t his competitors eat him alive on price alone? But Blake points out that “Giving is good for business.” He doesn’t see the need for a strict divide between ruthless for-profit companies and poorly-funded philanthropic arms or non-profits that produce nothing but good feelings. Blake is convinced that the model can be applied to other items besides shoes, of which TOMS has now given away over 1 million.

Says Blake: “When you incorporate giving into your business, your customers become your best marketers. It also increases employee loyalty and attracts great partners.” Blake turned the possible millstone of mandated corporate giving into an incredible asset. People are naturally drawn to products that make them feel good — especially when they know that their simple act of purchasing a product will put the same product in the hands (or on the feet) of a needy person. It’s helped him attract and retain talented and passionate employees and it has drawn him into the orbit of powerful people who feel compelled to give back. For example, Ralph Lauren designed his own line of TOMS despite having no financial stake in the company.

Does this business model have wings? I guess we’ll find out soon enough, because Blake teased us with the next product TOMS is planning on selling with a One for One model. He wouldn’t reveal what it is, but the world will know in June of this year.

Until then, let’s remember that not all marketing plans have to be top-down shouting machines designed to flood the marketplace. Most of the time, the best advocates for your brand are your own customers. If you can make a quality product and give back to the neediest at the same time, you’ll find the products almost sell themselves.