100.000 times people felt the need to ask someone for help, while facing a mathematical problem, where the motivation ranges from homework to pure mathematical curiosity.
Many of them (including me) found at least one answer here at Math.StackExchange.com. There recently was a comment that summarises it nicely:
Mathematics (SE) should be the most comprehensive, most visited, and most valuable mathematics resource on the web. I don't see a reason to shoot for anything less. [Amen]
So, thanks to all the people contributing in the past and good luck for the coming 100k...