MySql gurus... is this query ok (it works) top referrer

[grant.hayman]

I am using the addon that comes with vbadvanced for top poster to show top referrer for this month instead.

I have wrote this query to get the data that I need and it seems to work fine but was wondering if any sql gurus could check it over and see if it is the best way to do it as I am new to sql join queries (new to MySql in genral ).

SELECT ur.username, COUNT( user.referrerid ) AS totalreferred
FROM user AS ur
RIGHT JOIN user ON ur.userid = user.referrerid
WHERE user.referrerid != ''
AND MONTH( FROM_UNIXTIME( user.joindate ) ) = MONTH( now( ) ) 
GROUP BY user.referrerid
ORDER BY totalreferred DESC

Thanks

Grant