For advertising, it's all about display advertising and then requires constant unique reach. The real key measurement for them is engagement. What's your time spent, how many page views. I get NY Times Everywhere, but I still have to pay extra to get in it on my Kindle. That's ridiculous. Once you let the cat out of the bag, it's hard to get people to go back and pay for it.
When asked about how he would've done LOST differently, I would've liked to have had some additional writers who would do "twigs" off of the main story branches that might only live online. Our job on the advertising deal is to make the client & agency very happy, It's not the first deal, it's whether or not they come back again.
For brands that are still relevant today, ability to exploit all of the channels available is very powerful.