I noticed that in the original post, as well as including a neat article about AJAX, the author makes reference to job vacancies at the company he works for.
While he probably didn’t write the guide specifically as link bait for those positions (but who knows?), it very certainly has helped create free highly-targeted advertising and exposure that would normally require a hefty budget.
His post has made it to Ajaxian which has a huge tech based readership. I imagine those positions will be filled quite quickly.
An excellent example of good content getting noticed and achieving business goals.