Hundred Percent Guarantee!

Here's an interesting notice seen in Newspapers or at numerous places in Pune... Translated into English, it would mean - Courses for Spoken English with 100% guarantee. In the event of failure, full money back guarantee! So then what exactly does 100% mean? Typical, where we live happily with ambiguity in every aspect of life. Often 100% doesn't really mean "truly 100%"; but we understand the sentiment behind the statement and let it pass. PS: The title to the post just prompted me to listen to PuLa's Hundred Percent Peston Kaka for the umpteenth time :-)