Yeah I think Deadly Dan is confusing having a personal facebook profile and a company facebook page. I'd agree that for a professional to have a personal facebook profile and add their clients may be a bad idea. However, having a company page is very useful. And facebook isn't myspace, it looks clean and professional and can be perfectly appropriate.
Starbucks recently used Facebook to test out a new coffee flavour, basically engaging their customers, making them feel part of a community and that they have real input, and conducting market research at a very low cost in the process.
Companies that don't embrace social media may well get left behind, especially in certain sectors.
As to how to get more likers. Firstly make the page inviting, you can use FBML to create a welcome page to do that (Feel free to look at Hi Hosting's facebook page for inspiration - let me know if you have any questions), and then you can incentivise liking your page by giving exclusive discounts to those that do. Then post links to blog posts and other news on there, and engage your existing community. Make sure you have a Like button that links to your facebook page (you'll need to add your facebook page url in the like box generator) and put that on your homepage, as well as links in your footer if you like and so on.
Basically, make the content compelling, and then make sure people know about it.
Good luck!