
My response was that there was a very low probability of risk – the term “Top Ten List” is descriptive and therefore not generally protected by trademark unless it has acquired such distinctiveness that the term is pretty much only associated by one source. While, in certain contexts it is undoubtedly a very famous list, it is hardly the only place in which you can find people putting together lists of things in quantities of 10.
Further, there would need to be a showing that her use was so similar, that consumers were likely to be confused as to the source – i.e. people looking to enjoy a late night comedy show routine, were somehow distracted by her “Top Ten Reasons” and were confused as to the source of the information thinking it came from David Letterman. While it’s always important to make sure that you aren’t infringing other’s IP rights, it’s equally important to not let the use of descriptive terms by others prevent you from describing your own goods and services and sharing what you have with the world.