I know a lot of us had suspected it as it is something we do ourselves, we watch TV and view the Internet at the same time and a Nielsen report confirms it...
"According to the convergence panel, the heaviest users of the Internet are also among the heaviest viewers of television: the top fifth of Internet users spend more than 250 minutes per day watching television, compared to 220 minutes of television viewing by people who do not use the Internet at all.
Nielsen found that the reverse is true as well - the lowest consumers of television have the lowest usage levels for the Internet.
Nielsen also found that nearly 31 percent of in-home Internet activity takes place while the user is watching television, demonstrating that there is a significant amount of simultaneous Internet and television usage. Conversely, about 4 percent of television viewing occurs when the consumer is also using the Internet."
To me this means that an opportunity to engage viewers on both mediums exist for TV stations that can develop an outstanding and "sticky" web portal to capture and keep viewers once they are there and keep them coming back.