Second screen? Not so good for comedies; better for drama and reality.

Second screens in traditional TV living rooms can be good... and bad... and distracting. 

The bad for marketers? You might miss a few commercials or advertising messages. "Distraction does matter," says Rob St. Louis , consumer insights analyst of Hill Holliday, in speaking at OMMA Video Devices in Los Angeles.

And some TV shows simply don't work.

"Not all content is created equal," says Randy Shiozaki, co-founder of TVplus. " It's very hard to make a sitcom better. I don't know how you'd make '30 Rock' better. The jokes come too fast."

But Kirsten Atkinson, media director of TeamOne , says she sees scripted dramas and reality show offering up added value for consumers. Stacy Jolna , chief marketing officer of ConnecTV, says NBC's Summer Olympics scored great results from second screen content.