You can try the suggest friends trick .. just ask your existing fans to suggest the page to their friends if you want to make it viral. Cheers
Facebook is something i have to work on, my twitter (2000ish) and even myspace (3000+) is doing well and its not music related, but FB (75) all started about the same time.
I might be repeating myself in many threads, but again, Facebook Ads. The targeting options are there and with a few bucks, you can get a few hundreds of fan to get your page going. 100% spam free and professional.
To increase the no of fans on your fan page make the page informatics don't ever spam on it and keep away spammer. And one more thing no. of fans also depends upon the nature of your business
I simply give invitation to the person who are similar to my nature. Most of the time I get good response. You can also make bigger network through communities that are available on the orkut. There are communities of similar nature as well. So you can easily find one for yours.