Joe, I took a quick look at your site and you have done a lot of work on content. Also, I searched a couple of your topics on Google and saw information that you have created filling the first page of the SERPs on a variety of other websites. Sometimes your site is on the first page too.
Our approach is very different from yours. We produce a lot of content - as in your field the potential topics list is enormous. However, we never give it away. Everything that we publish is on our own website. Why? We don't like to feed our competitors and we want to be the "go to" source for information in our niche.
Consider this..... when I searched for some of your topics I saw your site at let's say position #5 but content that you created on the same subject on websites ranking above you. If they didn't have your content on their site then maybe your site would rank at postion #3 and thus be getting more traffic (and links, likes and tweets).
We spend zero time on linkbuilding.... 100% of our time on content building. All of that linkbuilding time (lets say you spend 50% of your time hunting links then spending it instead on content would double your content library and put you in the SERPs on twice as many topics and have twice as much content to impress any visitor.)
The only deviation that we take is to submit occasional... maybe once a month or two... items to sites like Reddit or slashdot or stumbleupon.. where we can quickly share new content with a large number of people.
The links arrive very very slowly... but content that we launched 18 months ago and that ranked in the SERPs on page three at the start is now ranking in the top three positions. These natural links are so much more valuable than links obtained by other methods. And they require zero time from us.
You can make links, likes and tweets occur a little faster by making it easy for visitors to share your content socially. We use the AddThis.com buttons to facilitate. They work great.
You asked what other people do for links... there you have it.