This is something that is often overlooked, and I think its one of the best question that comes to my mind for SEO. In order to grow it is important to insure that people will like the site so much that they will want to return but they will return when they come and so for making them come you need links and so how do you balance the Links Vs Content.
I would go with Build Content because the amount When you have good content Links tend to keep coming and your other half work is done automatically but its not true for vice versa
If you have time its better doing both. But if not, building content is much better. Google spiders like new content.
I go for build content!.. At the end, content is the most important thing!.. Visitors will be coming back and forth if your having quality and unique content!.. And agree to what they always say that content is king..
do them together, i mean build good content and all the SEO guys are very smart they know if they have created some good content, they will definitely add links to it, links with good content is always helpful, building only links would be by Forum posts/blog posts Directory submissions, the best way is to create good conetent and add them to good article directories and press releases!