He actually specifically said that if you get a great deal in a store, you don't have to pay ma'aser. But this isn't the same thing. This is more of an income, the only question is what is the actual value of the income. He had sources for everything, and frankly without the opposing view point of a qualified rav, it's hard to just decide you don't agree with him. I felt the person thoroughly understood the system. His questions were on the mark and to the point. If you're rav disagrees that's fine, but if someone just decides to argue, I don't really see how.
To clarify he was talking about CC miles. Miles earned via flying may be different. I will try and ask him.
I don't know the halacha about presents, but I would assume that this different because as he said, it should be viewed more as an income.
BTW. If you're doing a job that most people would do for free, and you are getting paid to do it, then of course you have to pay ma'aser on that. That was the way I understood his psak.