Not OP, but even today I still don't understand why is Dropbox different except for hype and media coverage - there were many similar services back then (including integrating as a virtual drive on Windows) and we have literally tons of these services now.
I read a quote of Drew's a while back that stuck with me. Just googled and found it:
"When Dropbox was getting off the ground in 2007, there were hundreds of small storage companies. It was almost a cliche, the way that many people believe mobile photo sharing is a cliche now, he says. “The important thing was, I would keep asking people if they used any one of these hundred options, and they all said no. These are my favorite problems to solve. You can’t focus on what everyone else is doing — it has to be about what’s really broken and what you can do to fix it.”"
He should've said what he did differently - seamless integration (aka virtual drive in Windows) was a selling point, but again, other services also had this.
You can find when each of these companies were founded by following the links...
Don't remember the name, but I remember similar service even in late 90s, when dial-up was popular. You'd pay for some amount of storage hosted on their servers (no "cloud" term back then) and they had Windows client integrated as a drive. Not sure if they had "freemium", maybe dropbox differentiated with this business model.