If your tutorials are as good as you claim them to be then your job is a lot simpler. Unlike promoting a squeeze page or sales letter/video, with a tutorial you can pretty much spam a lot of online platforms without getting in trouble. For instance, you can find groups on facebook and google plus today, post your content and get over 200 visitors today.
If you're struggling to promote tutorials then clearly you don't know where people in your niche/market hangout. Simply find where people in your niche spend a lot of time and be part of the community, or start your own community/group.
People are always looking for tutorials so they're the easiest thing to promote online.
All traffic sources work when used right and other traffic sources don't work for all niches including social media. People tend to think social media works for all niches, unfortunately it doesn't. When I get this type of question I no longer tell people to go use social media, forums, press release etc. because they end up being all over the place and never get the results they desire.
My advise is to simply know where people in your niche hangout, set yourself as an authority in those portals and enjoy free traffic. Also contribute don't just spam your content all day errrday.
Just to be clear, it doesn't have to be groups only, even forums or a blog that gets a lot of comments (you can set yourself as an authority in comments of popular blogs that are frequently updated). Even youtube has a really big and active community. Follow trends in your niche, be part of things happening in your niche, events etc.
Another great strategy I still use when I'm free is to attend live youtube broadcasts and G+ hangouts then answer all questions people ask before the person running the event gets the time to do it. They end up having no choice but mention my brand on their broadcast hehe
Hope that helps
