Lynda.com announced today that LinkedIn has acquired the tutorial website (CrunchBase) for an approximate value of $1.5 billion dollars. For LinkedIn, this is a major move.

LinkedIn earns revenue from recruiters has to keep a fresh talent pool. To keep a fresh pool of talented professionals, you need to keep the talent coming back. To keep the talent coming back, you need to be more compelling than reminding people that they’re jobless or convincing them that they are unhappy.

Job hunting isn’t a leisure activity. You really only used the site on a daily basis if you were a recruiter, or if you were out of a job. How many days a year are you out of a job compared to the number of days you spend working? So, LinkedIn’s biggest problem was keeping people interested.

In order to stay fresh in people’s minds, LinkedIn has sent out a deluge of email, more traditionally known as spam. Nobody likes spam, but nobody likes being out of a job either. It was a way to stay relevant. (This isn’t my assessment, but I can’t find the original blog post where I saw this.)

The Lynda acquisition solves the content problem for LinkedIn. By bringing 20 years of content into their repertoire, there’s a new reason to visit the LinkedIn family of websites. Professionals, especially the kind of creative professionals targeted by both Lynda and LinkedIn, are often self-learners. This will keep them coming back.

More than bringing back qualified professionals, the acquisition leads to some interesting possibilities too. LinkedIn + Lynda.com can run certification programs that teach the web development stack, for example, and then connect recruiters and job-seekers from that certification track. Another huge win for LinkedIn.

My only concern with such a program is that it may pave the way for under qualified individuals to work through an online course, where there is less accountability than say, a degree program at a university, and then snap up jobs via LinkedIn. (Beware under-qualified certification bearers.)

LinkedIn has just re-positioned itself from a find-professionals company to a home-grown-professionals company. In sports, we call this a farm system. For LinkedIn, this acquisition makes a ton of sense.