Worked for one that was at least in the top 5 porn sites back around 1998-99. All Windows servers running IIS and we were using NetApp appliances for storage.
Great site. What are some of the libraries you're using for this site besides using Ruby on Rails? It would be great if you can share on a broad level. I'm always intrigued by the speed of development with other solutions than using .net.
You need to think about the whole market size. What if the existing note taking applications like Simple Note are utilizied by only a tiny percentage of the possible market? Intead of just giving up, think of what other features you could introduce to beat Simple Note. Have you done any research to see how they are even doing? Don't be discouraged by competition. Google always pops up in my mind whenever I hear a story like this.