I wonder if Reddit would be what it is today without imgur. I started using Reddit shortly before imgur launched, and I can still remember the day that it went live. It was by far the best image uploading experience I'd ever had, and I'd used most (maybe every) major uploader that came before them, between 1995 and 2009.

It would probably be different, but not worse or better. I was there when Imgur launched, and at the time we thanked Imgur for dealing with the crap of hosting images (checking for child porn, dealing with DMCA notices and other copyright and privacy issues, etc). Had they not existed, reddit would have just done that ourselves.

Eventually reddit did do that themselves, but by then Imgur had their own community. I suspect some of those people would still be on reddit.