I would also prefer both, but then most blogs have a "no do follow" nowadays. Also it's easier to post in forums as you can find so many topics in one place. Perhaps, it would depend on your own preference.
Forum sigs are better, because its not all the comments you make on blogs that get approved. And forums are always indexed quickly.
Forum sigs are better, because its not all the comments you make on blogs that get approved. And forums are always crawled quickly.
both are good, if your active in high traffic forums then it can boost a lots of traffic and blog commenting also a good way to get traffic.
if you can use different methods then work with it..forum sigs and blog comments are just some of them..theres more
blog comments can fail so quickly... just one click of a button and your site can be added to the spam list - especially if you are using your keywords as your name eg. 'cheap viagra' or whatever.... all the owner of the blog has to do is to click - 'this is spam' and all you will see is a white screen next time you try and post. I dont think forum sigs are going to be that great either, but it will make you feel like you are doing some link buildign and bring you a bit of traffic. I'd just go for an article writer (hire someone) and an article distribution service (such as isnare) maybe that ang and paul thing, maybe a link wheel or just a few blogs and paid links (even though you are not meant to go for paid ones).
I prefer forum signatures now. The main is what you said, links from blogs may disappear or get deleted.
I'm doing both. I use blog comment to get back link to a specific page, not to the whole blog. For example, I make a comment on fantasy book review blog, and use the URL of the blog post, rather than the URL of my blog. In this case, the backlink is targeted.
For me, both are the same. To get people attracted to topic your blog focuses on, I prefer blog comments. Meanwhile, forum signatures can get more new visitors all together.
I have ran massive tests for both blog commenting and forum posting. In the end the direct traffic from sigs was next to zero. I got more direct traffic from blog commenting, but the problem with blog commenting is many of the blogs become no followed. The seo benefit is there for both but it takes a tremendous amount of effort to sign up to relevant forums, create an account and contribute something to the community, wherein blog commenting you don't have to sign up (typically) and can say a few lines and get a link.
Forum signatures can have a longer life. But if a forum isn't dat popular or big, not much of a use to you. On the other hand if the blogs are even knew, they have better chances of getting indexed and comment links would be found. And as some1 else said earlier, if your comment is one of the first few on a post, you do attract people's attention!
Both of them are powerful in SEO market. But I prefer forum posting because it normally does not ask you to wait for approval from the moderators. Until now, most of blogs are no-follow so it's not good for google index.