The only crazy part when it launched was the growing storage space aspect, which only seemed crazy because all the other mail providers were so ridiculously stingy. Email as a fantastic data gathering and ad platform made sense from day one.

I don't think they risked anything significant to build gmail. Nor was there any significant risk of gmail not succeeding due to hard technical problems. Compared to X projects like autonomous cars or power kites the original gmail was nothing crazy at all. Was it good software? Yes. Crazy? Hell no.