Backorder a domain name is very useful to do. This way you are almost sure you will get the domain you want. You can use it when you want a domain that is expiring soon. But, if the domain is worth some money, you have a big change someone else is watching to. I did a backorder on godaddy a few days ago and it was not successful. This is what happened:
I backordered a domain that was expiring from a internet company. It had a pagerank of 6. This was the main reason for me to backorder the domain. A domain with pagerank 6 can be sold for way more than the registration fee (or in this case: the backorder fee).
The backorder I purchased was $ 19. This is not cheap and it was my first backorder ever. I thought I would end up with the domain name, but I was wrong. The thing was: TDNAM (The Domain Name After Market) was catching the domain for me and putted my $19 as a start bid on it. Than everybody else could bid and so my starting offer was lost.
Now I am not getting the money back from godaddy. I can backorder another domain and hope I am winning it on the starting bid. The only domain I can get now is a worthless domain that no one else wants to have. Lesson learned