Uniques/Day Plummet in Second Half of April

For whatever reason my unique visitor count per day is plummeting. There have been five days since the 20th where I have had less than 100 unique visitors. I know that there can be no logical connection but it is almost as though since I introduced categorisations that my daily unique visitor count started to curve downwards, and this after about three consecutive months of an upward trend.

For a couple of months there I was getting regular counts over the 150 mark per day. Then about early-April they fell below 130, and as I say, in the last ten days I have had five days below 100—although the 28th was 99 which is only just below 100.

Oh well. I guess I will wait and see what happens in May.