The device itself more closely resembled a dumb terminal than it did a computer. It seems to have been pitched only as a way to get online, so it's not clear if it could do anything else.
This looked to be an awfully closed platform from the users' viewpoint. You could go to one of the numerous media, retail, or business pages, but there didn't seem to be any way for the end users to get online themselves.
Viewtron launched in 1983. At its peak it had around 15 thousand users. Knight-Ridder and AT&T reportedly sank over $50 million into ViewData, the tech startup that developed the platform, before pulling the plug in 1986.
But they did have ambitious plans. ViewData had also developed apps so owners of other computer systems could access the online platform. At its peak it had 15 thousand pages you could visit, and they had plans to expand to as many 100,000 pages.
Depending on how you measure it, they planned to have enough content online that you would now be able to fit on to a DVD.