I have been reading some confusion on this message thread. Comments are combining two completely different types, of programs. Let us first, clear up what these programs are and what their purpose is.
Webroot's SpySweeper, Lavasoft's AdAware and Kolla's Spybot Search & Destroy are programs that only look for Spyware and Malware ... not Viruses, Worms or Trojan Horses.
Grisoft's AVG is an anti-virus program, which only look for Viruses, Worms or Trojan Horses ... not Spyware and Malware.
Now, as to the validity of the Webroot company, they survived the '.dot com' 2000 crash and have grown in reputation and solid programs. They have been in existence, since 1997 and are well respected in the computer community.
About 2 years ago, I purchased Webroot's SpySweeper. My daughter had been using it, for a couple of years and loved it. I was impressed with it's over all performance. But, as one other person stated here, I didn't really want to pay an $19.95 annual subscription, for getting updates definitions.
However, both types of programs have a common thread ... the need to update the database definitions, as soon as they are available. Updating for these types of programs are paramount, in protecting your computer and/or computer systems.
I use Lavasoft's AdAware SE Plus. Why?Simple, it works and works well. Another thing, that I personally like about AdAware, I purchased their "Plus" program, about 5 years ago and they stated at that time, I would never have to pay for any upgrade. Guess what? They have honored that agreement and I like that. A company that stands behind their word, is rare these days.
Lavasoft's AdAware SE Plus, I allow it to automatically update. I have a DSL 6.0 Extreme, so, that is a no-brainer, for me.
I also, use Kolla's Spybot Search & Destroy, because it is FREE. Plus, it "catches" and removes the couple of odd ball spyware/malware, that may be missed by AdAware. Now, with Kolla's Spybot Search & Destroy, I manually update, before I scan. Where as AdAware uses only one location to update from, Spybot uses several and some just run 'slow as molasses'. Even with DSL 6.0.
Then, to finish off my PC 'clean up', I use Webroot's Window Washer 5.5.
I have been using Webroot's Window Washer, since early 1998 and will NOT be without it, ever. I dearly LOVE that program and trust it completely, since, I have control over the whole thing. I don't update the program. It isn't necessary, since it's only purpose is to remove "cookies". I was using their version 6, but, prefer version 5.5.
I really do love this program, you can set it up do all things automatically or you have the options to do it manually, which is my personal preference.
As to my usage of a Firewall, I have a fantastic one that came with my 2Wire DSL Modem. I am completely 'stealth' on Steve Gibson's Shield's Up scanner, at his website. I have used Zone Alarm and will only use the older version 2.6 of Zone Alarm Pro. The newer version plays havoc with Grisoft's AVG. However, I now only use the hardware firewall that comes with my 2Wire Modem.
Just for those who do not know, the term "Spyware" was coined by Steve Gibson. He became concerned in late 1999 or early 2000 about "spy-bots" that were in Real Player, that were installed on his computer without his knowledge or permission. His 'fight' is legendary and started a whole spyware/malware software industry.
A small note, these are my experiences with these programs, on my personal computers and what I use to install on family and friends computers, that I build, tweak and repair. As for corporate systems, it would seem to me, that the most important aspect would be to have programs that are easy to use, reliable and work.
Bottom line, Webroot is a company that I trust and use.