No forums for now. Only news sites and various blogs. Freddyjames covered his method extensively in the thread, and I'm following it.
Don't ignore forums. It is a lot more difficult these days to drop links on sites using the FB or disqus plugins, plus you won't get juice from them long term anyway. You can drop links in forums very easily as long as your post is a good one - especially if it's giving credit to a source (which is obviously your site, but they don't need to know that).
Forums also, as Meathead points out many times, rank very well, so you will get long term benefits from them. Comments sections from personal blogs also have good short and long-term traffic.
I can say the biggest single source of sales I ever made by far, long term, was one forum in my niche.
For commenting atm for IMMEDIATE traffic, at this point I would say that when searching for sites and news pages to comment on, pay particular attention to those who use their own commenting platforms. Sites like NYTimes, NYmag, washingtonpost etc spring to mind. Keep them bookmarked and look at them each day for new articles in your niche.
I used to do this each morning years ago, I think there is probably a comment here I made on it, how I would open any sites like this each morning while having a coffee, looking for places to drop links.
Facebook graph search is good for immediate traffic, however it is not as easy as it once was. If your account doesn't look real to FB, you're gonna be hitting ID requests and bans. I get around this with automated software, but that is really a different method.
Basically my point in making this post is this: Any form of IM is fluid. The rules change. What worked 3 years ago is probably going to need tweaking now to work in the same way.
This method of making money by driving traffic to your blog/site by making comments will always work, but you gotta be real smart now how you do it.
EDIT: I just remembered how a guy called Fukien used to make money, he'd register at forums and send people PM's that actually read "Wanna lose weight Fatty? Check this out ----> LINK". I wouldn't suggest that, but it does highlight how being original makes the most money.