The antivirus market is enormous, responsible for billions in revenue each year. That being the case, it'd be easy to believe that current offerings are quite good, but not so claims a report (PDF) by security company iMPERVA. This report states a couple of alarming facts, including one that shows that less than 5% of newly-crafted viruses are picked up by scanners right away. For most antivirus solutions, it could take upwards of 4 weeks before a virus is even added to a detection file. For software that promises to keep you safe, this is a disappointing statistic.
It's all the more disappointing when you realize that $4.5 billion is spent by consumers each year on virus protection, whereas businesses spent $2.9 billion. Combined, this money represents more than a third of all funds spent on security software each year - yet, it has some serious flaws.
On the upside, the report also states that some free antivirus applications offer the same level of protection as the commercial products. These excellent freebies include those from Avast and Emsisoft. It is however noted that each of these can also trigger a greater number of false-positives, which doesn't surprise me as I regularly see Avast doing that for people when I peruse comment threads around the Web for either software or games.
The report urges antivirus makers to focus on detecting virus behavior rather than just seek out whatever's listed in the definitions file, which seems reasonable to me. While it's highly unlikely that you're ever going to contract a computer virus within the first month of its release, it could happen, and it'd be nice to know that the ~$40 license you purchased is actually going the extra mile to protect your system.
With all this information, you may be led to believe that virus protection simply isn't needed, but iMPERVA doesn't recommend getting rid of it. Luckily, the fact that the company backs up some free solutions means you can score fairly reliable protection on the cheap.