Visa run implies getting a new (tourist 60 day) visa at a Thai Embassy abroad .. you can extend this for 30 days at any immigration.
Otherwise
The 30 day- entry stamp you get a the border is a visa exemption and not a visa on its own. You can also extend this for 30 days at any immigration. And yes you can do so twice a calendar year, best to stay out a few days otherwise they suspect you are working because of swift return and might give you some hassle.
I have the feeling you did not extend yet with 30 days at Samui, am I right?
Nance Its possible as digital nomad or whatever work you do to register a company in Thailand which grants you a "business" visa with 1 or 2 workpermits.