Here is another reason why you cannot get a Facebook username for your Pages – You need 1000 fans to be eligible to get a Facebook username. And if you have over 1000 fans today, it wont work because you need those 1000 fans before 31 May 2009!
Mashable says if you check the eligibility criteria, it seems eligibility is limited to anyone who joined Facebook before usernames were publicly announced at 3 p.m. (EDT) on June 9, 2009 – and only these users can claim usernames at 12:01 a.m. (EDT) on Saturday, June 13, 2009.
Those who joined Facebook after the cut-off will be eligible to claim usernames on Sunday, June 28, 2009. This precaution is taken to prevent people from creating new accounts just to squat and reserve Facebook username. So before you line up new Facebook accounts, note that you cannot claim your username on June 13.
After top journalists got priority usernames and bypassed the queue while the world awaits, this fine print is another blow to most users. There are so many factors, and so many people competing to get your Facebook username, that you will indeed be lucky if you manage to get your desired facebook username.