Well that technically isn't an avast function built into avast, but a browser add-on by avast.
And what is it for the others antivirus?
That should be written in the comparison chart.
Well aside from the fact that it is a) currently only a beta, b) isn't integral to avast it is only a browser add-on, so we really can't jump the gun and say it is something that it isn't.
Not to mention what category would you be putting it in, in the Comparison list as suggested ?
I can't see a category that fits, so I can't see what other AVs would be calling it in any comparative category. There isn't a category for Web Reputation or anything close that I can see.