ExoLocal charges as little as possible to provide their customers with a high quality service. They only offer local marketing and charge $18.95/month for it - because that's what we're great at. There's no upsells or downsells.
They basically provide the same service as SEO companies that charge around $300/month. The reason they're able to charge so little is because they don't offer any sort of reporting or phone support. Instead, they spend all of their time promoting your business.