That's quite good. Really, I think that most proxy sites out there are getting around 200 uniques per day(There are some exceptions). Try to get some links in myspace related websites (a lot of proxy users are kids trying to access myspace from school). PS: How much bandwidth are you pulling?
800+ is decent how old is the site?, i've had some in the past that hit 1 million page views a day in the past, traffic came from some wierd forums not in english lol, but adsense was a killing