Apparently, Americans love combining their technological obsession. 40 percent of smartphone and tablet owners say they use those devices while simultaneously watching TV every day, according to Nielsen. 88 percent admit to having done it in the past at some point in their lives. All this is another way of demonstrating how essential such devices are becoming even in the most passive of daily activities, like TV watching. Yesterday we noted that wireless devices such as tablets and smartphones now outnumber human beings in the United States, something that's never been the case in the history of television.

Nielsen's advertising clients will love the fact that 19 percent of such multi-device users say they search online for products they just saw in an ad. But for the most part, people's online activity while watching TV is pretty boring: 60 percent say they're checking email, while 46 percent say they're searching for content unrelated to the ads they're seeing. (Full breakdown charted out below.) In contrast to tablet and smartphone users, those with e-readers in their hands clearly have better attention spans, with only 14 percent saying they simultaneously e-read and watch TV and 45 percent saying they never do it.