Some yes, maybe some not. But a lot of news from them who get a large income from PPC. Although the PPC provides a low fee, but you could try to prove it.
Yes, i believed quite number of the members live with PPC advertising. Some of them actually pay good rate such as adsense
They will pay so low due to the economic crisis. But you still be able to live on PPC if your are a great publisher who has multiple blogs flooded with lots of traffic.
Some PPC sites pay alright, but unfortunately then some people don't stay with them and have to use low ppc sites instead. Reason is they see the good earnings and start to cheat a bit and then go bit to far and get banned. To make money, don't cheat and then you will be able to live from it.
I used to get $2 per click on my site with adsense and since this month, its dropped to about only $1.10 per click... very depressing but yes, I do this full time.