We have noticed a large increase of (direct) / (none) traffic in Google Analytics since May 9th.
The traffic seems to be "spiky" (e.g. one day 25% of traffic, another day 10%). Most of the data points about this traffic are not present. We can say 80% come with a user agent of "Mozilla Compatible Agent" or simply "Mozilla". The bounce rate of such traffic is near 100% and the time on site is 10 to 20 seconds (could this because tracking is not working properly?). The pages hit seem to follow human usage patterns or a VERY sophisticated bot (however, we employ numerous anti-bot methods). 95% of traffic is reported as originating from the United States (our target market).
Ideas on what this might be?
[edited by: venti at 10:36 pm (utc) on May 29, 2012]