After my porn site fiasco, I built v1 of Uploadfiles in a weekend from a beach in Koh Phangan, Thailand, initially utilising AWS s3 as the file storage and delivery (a hard lesson learned).
V1 was a simple one pager, with a drag & drop file uploader that returned short URLs on upload completion.
No marketing or hard launch, I simply posted it on Hacker News and Reddit. Our first month saw 6,230 page views. By month 6 this was 500,000+ monthly page views.