I worked at Basecamp/37signals up until 2015. We had peaks and troughs, with as you might predict traffic ramping at ET morning, and tailing off PT afternoon/ev

I worked at Basecamp/37signals up until 2015. We had peaks and troughs, with as you might predict traffic ramping at ET morning, and tailing off PT afternoon/evening. We had some European traffic, but it was substantially less than the US. It still cost /far/ less to buy/rack/power etc. our servers 100% of the time than it would have done to use the cloud and scale up and down with demand. There is definitely a situation when bursty requirements will make cloud the more obvious answer, but given the near order of magnitude cost increase for cloud it's not as clear cut as just seeing a wave on a graph :)