Off-topic. What's up with Frankfurt? 3 of 5 cloud companies compared here have Frankfurt listed as their European data center location.
International airport https://en.wikipedia.org/wiki/Frankfurt_Airport
https://en.wikipedia.org/wiki/Frankfurt
International finacial center. Like second financial center of Europe after London.
Today it still makes sense to go there because Germany is the wealthiest country around, and from there you can serve the entire Paris-Brussels-Amsterdam-Frankfurt area, which includes a lot of people: http://kids.britannica.com/comptons/art-143547/Population-de...
edit: before I get punched by an autist, Frankfurt not ON the Rhine, but it has an incredibly quick access to the Rhine without being subject to its floods.