To put this into perspective, there are now over 50,000 registered users on the AIS site. In the last year there have been an average of 19,200 log-ins per month with 16,500 briefings delivered per month.
Out of interest, and this is not intended as yet more AIS-bashing, are there any figures for the number of briefings provided by Avbrief for use with Notamplot? It would hopefully be quite persuasive if the third-party solution was more popular than the official source.
I always check Notams for any flight out of the local area, but rarely use the AIS website because the Avbrief/Notamplot combination is so much easier to use. It sounds from the figures that most people either don't read them at all or feel the same way - if we all read the NOTAMs from the AIS website I would guess that there would be a lot more than 16,500 briefings a month (equal to one every three months for each registered user)?