It’s no joke. Facebook will ban you for doing business on your timeline. Here are their exact words on the matter:
“You will not use your personal timeline primarily for your own commercial gain, and will use a Facebook Page for such purposes.” —Facebook Legal Page
There are several reasons why you should not be focusing on promoting your own business and perhaps the most important is so that your Facebook Timeline isn’t spammy.
The key is to share those items on your Timeline after you post them on your Facebook Fan Page or Business Page. You can also just post them on your Fan Page which is what Facebook really expects, but either way is fine.
There are benefits to this by the way such as being able to track your reach of your posts and increasing likes for your business (distinct from your personal profile). Your personal profile does not have social graphing and analytic features like your Fan Page does.
While you can promote certain posts on your personal Timeline, you don’t have the ability to promote/advertise the way you do on your Fan Page, so it’s just going to be better for you all around if you can just keep it between the lines so to speak.