Ah, the holidays are upon us.  And, as we all know, 'tis the season for piles of spam!

Or is it?  Last year, we saw a very large run up of spam heading into December, but in the month of December itself I saw nothing out of the ordinary.  Here is the breakdown for the week starting the below mentioned day and the week-over-week % increase:

02-Oct-2006      14.63%
09-Oct-2006      13.22%
16-Oct-2006      7.97%
23-Oct-2006      5.44%
30-Oct-2006      9.08%
06-Nov-2006      -0.22%
13-Nov-2006      2.21%
20-Nov-2006      -0.60%
27-Nov-2006      4.24%
04-Dec-2006      0.40%
11-Dec-2006      8.80%
18-Dec-2006      1.27%
25-Dec-2006      -22.18%

Note that while the total traffic went up in December (other than Christmas, where everyone clearly took the week off, including spammers), traffic was going up for each week before that.  In other words, December was spammy, but so was October.  Furthermore, the weeks in January and February (excluding the first week of the year), total email traffic was about the same as it was in November and December. 

However, the two week period of Dec 11 - Dec 25 did contain the highest traffic totals, so perhaps there is some truth to the theory that there is a spam blitz in that period.  Let's use the week of Nov 6-12, 2006 as a baseline:

06-Nov-06    1.000
13-Nov-06    1.022
20-Nov-06    1.016
27-Nov-06    1.059
04-Dec-06    1.063
11-Dec-06    1.157
18-Dec-06    1.172
25-Dec-06    0.912
01-Jan-07    0.890
08-Jan-07    1.048
15-Jan-07    1.114
22-Jan-07    1.054
29-Jan-07    1.161
05-Feb-07    1.044
12-Feb-07    1.046
19-Feb-07    1.112
26-Feb-07    1.038

If the December/spam theory were valid, we would expect to see a large spike in December and then see the numbers subside afterwards.  In fact, we don't see that except in December 11-25.  Afterwards, the numbers are wildly erratic, but Jan 26-Feb 1 is nearly as high as the supposedly high spam period.  There's nothing particularly holiday-like about that period of time.

Thus, while I'm not about to call this a myth yet (I still have to check 2005), I don't think there's a lot of evidence at this point to say that December is truly an extra spammy season.