Anyone using Facebook probably has a hard time keeping track of all the changes and updates to the service.

Even those of us who use Facebook for business are hard-pressed to keep up. In the last few weeks, I’ve learned more about Facebook through trial and error (and my Twitterstream) than I ever have from Facebook’s communications. Here are a few things I’ve learned that you may not know:

Not interested in having a Facebook account of your own (a personal profile)? Facebook has finally given individuals who only want to use the site to administer Pages and their ad campaigns the ability to create a non-public Facebook account without an attached profile. A Facebook business account gives you access to the Pages and the Social Ads you manage.

To create your business account:

• Go to Facebook and do not sign up for an account. (Note if you have an account already and then try to create a Business account it’s a violation of Facebook’s Terms of Service.)
• Create a Facebook Ad or Facebook Page.
• At the “Facebook Login” page, you’ll be asked if you have a Facebook account. Select “I do not have a Facebook account.”
• Enter your email address and date of birth.

Voila! You have a Facebook business account attached to your Social Ads and Page.

2. You can “tag” a Facebook Page in a status update.

By using @ mentions in your Facebook status updates, you can “tag” people who will then be notified that you’ve mentioned them. You can also address an @ mention to a Facebook Page, Group or Event from your status updates. Just type in the @ symbol followed by the first few letters of the Page, Group or Event you’d like to mention.

3. You only need 25 “fans” to get a custom “username.”

There was a time when you needed 100 “fans” or “likers” on your Page before Facebook allowed you to get a vanity URL or Facebook username. Now you just need 25, which shouldn’t be hard to get.

4. If you restrict access to your Facebook Page, your Page ceases to be public.

You can restrict your Facebook Page to a certain geographic location or certain age group, but if you do so, you no longer will have a publicly-viewable Facebook Page. Even if you have a Facebook vanity URL, the page will default to the Facebook homepage if a Facebook member does not fit into the criteria of your restrictions. If the visitor is not a Facebook member, they cannot see your Page at all, because Facebook has no way to verify if they fit your criteria or not.

5. Neither Pages nor Groups have limits to people who can like or join.

There was a time when Facebook limited the number of fans or members you can have on your Page or in your Group, but now the sky seems to be the limit. I’ve seen Pages with over a million fans such as NPR’s Page. You still can only have 5,000 friends on your personal profile, though.

6. You cannot send a direct message to the fans of your Page.

You can speak to all of your fans via your Page’s Wall, but you cannot broadcast a message into their Facebook inboxes. Instead, you can send your fans an “Update.” Updates only show up in a subsection of Facebook’s Messages page. You have to know it is there, and click the link on the left side of your screen to access the Updates. Note that Updates do not get sent to people’s actual email accounts. If you have a Facebook Group, you can directly message your group members; this message is sent to both their main Facebook Messages inbox and their personal email accounts.

7. You can add Google Analytics to your Facebook Page.

If you have a custom Facebook Page and are hosting some FBML code on your own server, you can use this technical workaround to add Google Analytics to your Facebook Page. The programmers who created this also provide a Google Analytics link generator to help you create an image (IMG) tag for each Facebook Page you’d like to track.

8. You can see how much website traffic your Facebook social ad generated.

Have you created a Facebook social ad that leads people away from the Facebook site? Facebook but now offers a conversion tracking system. You might have already seen a mention of this feature appear on your Ads Manager page; it will measure what happens on your website once a Facebook user sees or clicks on your ad. You can access Facebook’s guide for this new feature which is currently in beta.

What is something new or surprising that you’ve recently learned about Facebook?