It looks like Facebook has finally lowered or removed the minimum number of fans required to register a vanity URL for a page.
When the vanity URL feature was first announced, a page needed 1000 fans. Then they reduced it to 25 fans, but only for a short time. Without warning, the limit was increased to 100 fans, so my pages weren’t eligible.
Today I noticed a vanity URL announcement at the top of a page, so I went back to www.Facebook.com/username to try again.
This time I was successful, and now my Facebook pages have vanity URLs:
http://www.facebook.com/Contextures
and
http://www.facebook.com/PivotTables
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