Of course you can!
For example, imagine you want to resell hosted Ecommerce turnkey solutions to your customers. You use an app that runs in PHP on a MySQL database, and you know how to use an API. Then it's easy to offer Ecommernce solutions to your customers with Simple Hosting.
A simple command (paas.create) lets you create an instance. Another (paas.vhost.create) associates a domain or subdomain of your choice to the instance, and you then directly upload the code for your app to the the vhost, using sFTP. Presto, your customer is online in a few minutes! If you are short of instances, or need to beef one up to a larger size, the API supports commands to buy more resources as well.
Our API is XMLRPC, and supports many libraries. Lots of programming languages are available for accessing it (PEAR, for example, or PHP, or PERL).
Wondering about prices? Well, we've not implemented any sliding scale or reseller price breaks (mostly because the price is so low already) but, if you decide you want to resell our solution to your customers, either via the API or via the website, you can always contact us (firstname.lastname@example.org) to see what we can do for you.