There is a link building section of a freelancer site where I have gone to get some content writers. The content writers have done what I asked for, and I have gotten good results. I'm intrigued by the link building section. People post things like, "100 PR5+ Perm 1 Way Links" and then the freelancers bid on that project. I'm wondering, though, whether this works or will be worth it. If I were to pay a freelancer to do that, I don't want them spamming a bunch of sites, or doing something that could get my site into any sort of trouble. I'm actually rather puzzled about how they would go about doing that work. Has anyone used these link builders? Have they done what you asked and have you acheived the results you are looking for?
Getafreelancer.com is the place that I've used in the past, and the place where I see these projects being done on a regular basis (maybe that should tell me that it works...but I'd like to hear from someone who has had experience...)
I don't think you should ever outsource your link building.You never know WHERE your link will end up.
There are some good companies that can get you quality backlinks but they usually charge between $50-$500 per backlink. Everything that's bellow this price, it's a scam. Just think about how hard (in most cases) it is to get a good backlink. Would you do it for $10 (like the most companies on freelancing charge)? I know I wouldn't.
I would suggest you to get your own list of sites where your links should be (articles...) then ask the freelancers to submit your link in there. Also you can control where the freelancers submit your links by asking them where are the links
100 PR5+ revelant and permanent links isn't easy to get and not cheap. Ask them for some example sites of where they post links...