robzilla - 10:51 am on Jul 24, 2008 (gmt 0)

I've been seeing the exact same thing for a while now (not sure when it started). Interestingly, all hits have a referring URL that includes the variable "form=QBHP". I say hits because I don't believe these are actual visitors. Google Analytics does not count them as visitors, only my server log analyzer does (severely skewing my stats on some days). I just did a quick search on QBHP and eventually ended up at an old WebmasterWorld topic from August 2007:
[webmasterworld.com...]

These hits are not all made from the same IP, but all IPs seem to fall within the same, or very similar ranges, and the user agent is always "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; .NET CLR 1.1.4322)".

More related topics:
Possible Bot or Spammer [webmasterworld.com]
Concern with spammy search words [webmasterworld.com]

So now we have QBHP, LVSP and LIVSOP. Doing a search on "LIVSOP," I found a response from an MSN employee:

The traffic you are seeing is part of a quality check we run on selected pages. While we work on addressing your conerns, we would request that you do not actively block the IP addreses used by this quality check; blocking these IP addresses could prevent your site from being included in the Live Search index.

Source: [exposureonline.com...]

All keywords I'm receiving hits for do occur on my site, so it is possible that Live is performing such quality checks on, say, hundreds or even thousands of pages that appear in their search results for a particular keyword, so even though your page may not rank within the first so-many hundred results, you will still see these (human-like) requests.

I've seen some people call this a cloaking detector, which might explain why these hits look human, but aren't.