I am aware that backlinks have different SEO-values corrosponding to wether the content of the site the backlink is located on relates to the site the backlink leads to. My only question is: Can backlinks affect your search engine ranking negativly if they are located on sites not related to your homepage? To take an example... if I posted my website about gaming in my sig on this forum, which has nothing to do with gaming - could this affect my websites ranking?
As long as your links are on quality pages, then you're not going to get negative marks. Keep in mind, though, that just because it isn't negative, that doesn't mean it's going to positively affect your SEO, either. In summary: no, it can't hurt.
No, it won't affect your site ranking for as long you're linking with a site that has good reputation and link popularity.
Yeah if you get many links from unrelated sites then it really might affect the ranking of your blog or site.
Yes, they can. And there's been talk that some competitors will even try and use these unrelated links against you. I've seen it done.
From my understanding it does not affect your site negatively, but it really does not improve your pr help to much either. In regards to competitors putting links on "bad Sites" to affect a sites pr and serp rankings..... if that was true than no one's website whether business related or not would really ever have a high pr or serp for a long period of time because all of their competitors will try to bring them down via "link spamming".
If I understand, the possibilities are negative effect, no effect or positive. You're willing to accept neutral, because you're not posting here just to get PageRank. It does not make sense that just posting links in an unrelated place could cause negative PageRank. Like Registernuke says, it would be happening all over the place. But in the second place, there is no incentive for Google to penalize on something that your competitor could do to hurt you. Google's concern is the results it presents to its own customers. Once you really understand that logic, then you can see that they're not going to do something that could hurt those results--like having competitors waging link wars on Google's pages. Maybe it's my current coursework in statistics and logic, but this seems like a pretty clear case where Google would naturally give neutral or positive influence, not negative. They're not going to give you negative points for something that you are not able to control. That would not be in their best interest or their customers'.