I think for actually downloading new software, this is kind of pointless. Anybody could just go to whatever website the software is on, and download it. What I think this would be useful for is finding new / useful software.
Take CCleaner for example. I never would have known it existed had someone not told me. Same goes for quite a few other programs I use all the time now (Handbrake, GIMP (I have PS now but still), etc.)
I guess you could use CNET (google, even) to find new / useful programs, but from what I've experienced, download.com has a lot of, well, crap. A few weeks ago, I was looking for a RAID recovery tool, and every single one I downloaded from download.com was a limited trial, and wouldn't actually recover anything until you bought the full program. Totally useless.
Either way, if you like it, use it. If you don't, disable it (uninstall?) and move on with your life 😛