Actually tkshatru, it was PEN. Not sure if I'm allowed to mention that company anymore. Here's a link to a BRR interview post. Gus gives a bit of an explanation from about 1min to 2min so you just need to listen to that bit if you're interested:
http://hotcopper.com.au/post_single.asp?fid=1&tid=1282654&msgid=7221161