Facebook adds the following caveat to their directions for these "Page building" tactics (emphasis mine):
*Note: We will not store your password after we import your friends' information. We may use the email addresses you upload through this importer to help you connect with friends, including using this information to generate Suggestions for you and your contacts on Facebook. If you don't want us to store this information, visit this page.Will they also be selling these people's information like they do everyone elses? Of course.
So while this may sound like a tempting way to quickly amass a Page with a bunch of "likers" directly imported from your database, I personally wouldn't touch this with a 20 foot pole. I know that I'd be pissed if any association I was a member of imported any information about me into Facebook--or any public site, for that matter.