You are referring to the "mobile tab access" Vitrue announced this week? :)
What they are doing is this (basically):
- Create a special link to the tab (
mydomain.com/tablink1
or something, NOT the ?sk=app_xxxx
URL in the browser bar)
- On that link they have code which does a conditional redirect
- If it's a regular browser/device, redirect to the tab (
?sk=app_xxxx
)
- If it's a mobile browser/device, redirect to an alternate mobile webpage with the same content as the tab (
mydomain.com/mobilecontent1
)
The redirect is not on the actual tab, since the mobile browsers will never get there. It has to be on a separate page.
So if they try to access the tab on a mobile device with the regular tab URL they will not get redirected. It only works if they go to the special redirect URL. Vitrue's application publishes that special redirect URL to the Page wall.
It works very well to make sure everything you post to your Wall (which mobile users can see) does not break, but it does not really provide a redirect for mobile users trying to get to your tab.
That's the best we can do right now though, until Facebook actually comes up with a mobile tab solution (bug filed here: https://developers.facebook.com/bugs/264010470314544)
Good luck!