Only once did I try, sent a request via their site, received a reply my name was acceptable ( of course, as it was a generic one word ) they set a reasonable price and said they would contact me within 2 days..... NOTHING, no call, email, letter...NOTHING. I waited a couple weeks than moved on and sold it myself.
So in short, like anything in life, people make mistakes, forget etc. If this is your business however you cannot afford to forget too often.