In general, I imagine the same set of marketing practices would apply to reseller sites as they would any other website. You need to set yourself apart from the rest of the crowd and offer value to your customers. By offering them just products or services without substance, it would be hard to build trust.
Blogging, paid marketing, video marketing, podcasts, content generation are all ways to reach customers. LinkedIn would be a great place to find businesses looking for a lot of web help.
However, a great way to do this is when you are working with clients on any web-related areas you can present the GoDaddy products as part of your product portfolio. This will help them work out the decisions on what host, registrar and SSL certificates to use.
I hope this helps.