Just for the record, here‘s John Slattery who plays Roger Sterling (a personal favorite of mine) in a Q&A for The New York Observer. I wanted to highlight his answer on how much smoking the Mad Men actors actually do for the show:

Off topic, can you please tell me what the deal is with all the smoking?

We’re smoking herbal stuff. They’re not very pleasant, but they’re not addictive because I used to be a pretty heavy smoker. I love it. I miss it. If those things weren’t so nasty, I’d smoke those.

Can the real smokers smoke real cigarettes?

The people who actually smoke, they smoke those things and then go outside and have a cigarette. [laughs] You just don’t get the same zoozsh.