Is it enough to let links come to your website naturally? Some search optimizers advise producing the best content you can, and allowing the links to come to your content as naturally as possible. If you’re patient and your content is exceptional, this can work, but it’s faster, more reliable, and more efficient to build at least some of your own links. It’s also more pragmatic to work on building links in addition to passively “earning” them; if your competitors are conducting link building campaigns (and if they’re doing well in organic search then they almost certainly are), but you’re sitting on the sidelines, it’s going to be tough to keep pace with them in the rankings.