FAST SharePoint Search
When I set up FAST in my SANDBOX/DEV SharePoint 2010 environment I was having some issues with search not returning any people results. Troubleshooting the issue let me dive deeper into understanding the roles of the Content Search Service Application (SSA) and Query SSA that are setup when configuring the FAST Search Connector and FAST Search Query Service Applications.
Visual representation spells this out:

So the Content SSA is responsible for all Web Application content and the Query SSA is responsible for People Content (represented by the sps3 prefix which is a SharePoint specific code for people profiles content) and both these SSAs have their own Full and Incremental crawl schedules.
When you provision new web application(s) the URL will get appended to the Query SSA which will need to be moved to the Content SSA properties screen (see highlighted area in the Content SSA screenshot).
RESOLUTION TO NO PEOPLE RESULTS:
Run a full/incremental crawl on the Query SSA. I kept running the Content SSA crawl thinking it was responsible for all content including People. Once the Query SSA crawl ran I was able to see People Results:
I discovered your blog site on google and check a few of your early posts. Continue to keep up the very good operate. I just additional up your RSS feed to my MSN News Reader. Seeking forward to reading more from you later on!?
Greetings, this is a genuinely absorbing web blog and I have cherished studying many of the content and posts contained on the web site, keep up the outstanding work and desire to read a good deal more stimulating articles in the future.
Super-Duper site! I am loving it!! Will come back again – taking you feeds also, Thanks.
Man, talk about a fantastic post! I?ve stumbled across your blog a few times within the past, but I usually forgot to bookmark it. But not again! Thanks for posting the way you do, I genuinely appreciate seeing someone who actually has a viewpoint and isn?t really just bringing back up crap like nearly all other writers today. Keep it up!
Thanks for creating this. I really feel as though I know so much more about the topic than I did before. You should continue this, Im sure most people would agree youve got a gift.
Great post. Query Crawl fixed People Search no results. It saved me a reinstall. Now I can start adding by line of business sources via new BCS. Thanks/George