Hi Bryan
Their service (called a "snapback") basically gives you a
chance to grab a domain that is expiring. The fee is $69 and is non-refundable although, if they aren't able to get your domain, you can transfer your snapback to another domain and so on for up to twelve months..
There are several similar services available, including:
www.namewinner.com
www.namefox.com
www.dropking.com
www.expirefish.com
Plus there are many private operations (eg BuyDomains.com), so competition can be strong for good domains..
SnapNames seem to be the most consistent, at least for me over the last few years. Today they got me actress.org
The general advice on here is to use as many services as you can afford, if the domain is worth owning. It's just like buying lottery tickets - the more you own the better your chance of winning.
Hope that helps,
Chris.