Zoe, from Jobsyntax, had a great post that enumerated some reasons why groups/companies may have a hard time hiring folks. 

The JobSyntax Blog : top 10 reasons why employers have a hard time hiring good talent.

Here were some of my favorites…

1. You don’t have a marketing plan – Every good business selling a product has a marketing plan for how they are going to reach their target audience. Think of your jobs as your product…

I’m waiting for our team’s super cool posters to make their appearance in our building. It may seem lame, but I really do think you can create a buzz, even internally to MS, if you can be creative.   

4. You're not making finding great talent part of your everyday job – Hiring managers and recruiters alike tend to wait for jobs requisitions to open before they begin the process of recruiting.

You’d be surprised how many people you work with on a regular basis may someday hit you up for a good opportunity. Just something to keep in mind when doing a lot of cross group work at Microsoft.  You should always be on the lookout for passionate people in other groups that you know would make great additions to your teams.  This is yet another good reason to always try make great impressions.

6. You don't prepare well for interviews – You expect the candidate to come in well researched and understanding not only the position, but your company as well. What is your understanding of the candidate coming in to meet you?

It may take more time, but one of the things our group does is engage in both pre-and post interview chats about the people coming in so that we can all be on the same page. 

10. You are not investing yourself in the community – When I say community I mean the groups of individuals that make up the target market you are trying to reach; current and future.

Yet another reason to go help customers be more successful in our communities.  You never know where you’ll meet the next David Kean.