When we first launched “Nature Protocols “:http://www.nature.com/nprot I was keen to get our protocols indexed by all the big players. Whilst there was going to be a marketing campaign with ads in Nature and banner ads all over nature.com I knew we’d only get real users when people did their literature search and one of our protocols came top of the list. We wanted to be something researchers needed and found useful. However, alongside getting listed in the ISI Web of Knowledge came the news we’d also be eligible for an Impact Factor. It was clearly something scientists cared about. A lot of our early correspondence was about what our Impact Factor was.