Yes. Download.com is the 173rd highest traffic site in the world. They're probably pushing over 100-200k downloads a month at least. Nothing compared to the Apple or Android app stores, but still a significant number.
I pulled my apps from download.com years ago because the traffic was neglibile. It's probably alright if you are in the top ten for a category, otherwise there are much better ways to promote your software.
I'll often use File Hippo, but they've always seemed "cleaner" to me somehow. I even use their updater on some computers, which I wouldn't even consider doing with those other sites.