Selected answers from the Dumb SEO Questions Facebook & G+ community.
Christine Hansen: If you find the right match between you, the company, the services they provide, and the price tag, it could be a great thing if you do not have the time for it yourself.
Ammon Johns: In theory, it can be. In practice, it rarely is, and most outsourced link-builders, other than the best and most reputable, the ones cited often by knowledgeable reputable SEOs, spend a lot of their time, and your money, on building links that are, at best, worth little to nothing, and at worst, often have an overall negative effect.
There are thousands of so-called SEO companies and individuals who call themselves `link builders` and those I would ever trust with a project can be counted on one hand.