Just wondering from a backlink perspective about something. You as a human will have a wide range of interests and say you have a website about perfume yet you go onto blogs about cars, video games, women and so forth. You leave insightful comments on these blogs because you have an interest in those topics and in the website field you drop your url. How much benefit do these links have ? I know it is good to have links in related industries but can they cause harm ?
They won't do any harm. I think the best thing you will probably gain from this is traffic and a few backlinks.
I like links from any site but relevant helps the best. So just find relevant blogs and forums and use your signatures and link comments to help gain in the serps. Even if the link is from a non related site it still helps just not as much I believe and probably most do no the forums. But as always said a link is always great for a site