My FaceBook Page is setup so that users who have not \"Liked\" the page yet (and attempt to view the page) are presented with the content of a particular tab instead of the
Apparently like buttons aren't supported in the current implementation of FBML, which is the only language you can use inside the "tabs" on a facebook canvas page. You may notice that a number of professionally done sites put a big arrow pointing up and then a "click the like button" text, without actually using a like button. This is why they do that.
Until facebook implements XFBML inside tabs, it looks like any XFBML only tags (such as fb:like) can only be used on your personal website. I think they do this for security reasons, although it does seem a little ridiculous that there are features you can use on your own page that facebook doesn't actually support on -their- pages.
The only workaround I have found is to include fb:comments tag in your app, which is an FBML tag that puts up a comments box AND a like button.
First of all, make sure you page is loaded in html mode instead of FBML.
1, Load the FB JS
<script src="http://connect.facebook.net/en_US/all.js#appId=YOURAPPID&xfbml=1"></script>
2, Init the FB (sometimes it doesn't work without this)
<script>
FB.init({
appId:"YOURAPPID",
xfbml:true,
status:true,
cookie:true,
});
</script>
3, Put the like button where do you want
<fb:like href="http://www.facebook.com/YOUR_FACEBOOK_PAGE" send="false" layout="button_count" width="90" show_faces="false" font="arial"></fb:like>
The like will appear, but will not make page refresh, so you have to take care the flow yourself.
In order to get a Like button, go to http://developers.facebook.com/docs/reference/plugins/like, fill out the appropriate information and press "Get Code". This will open up a modal window with the necessary code. Copy that code into your program, and you're done.