When do you see traffic going down, by how much and how long does this period last before things get back to normal? I meant to say For webmasters
Generally my traffic goes down in summer, not winter. When it's out of season it can take a few months or more for things to pick up. One thing that may help is if you have a part of your website that could be more popular than it is now, pay extra attention to SEO type stuff like: the text used to link to that page, is it easily accessible from various places on your site. That sort of thing. But that's for parts of your site that are underperforming. When a whole site is underperforming a combination of editorial stuff like: is my website actually interesting to people, SEO and marketing (forums, myspace etc) would tend to help. In general though: sometimes loss of rankings just can't be helped, because the other sites are getting better. In that case it's a good idea to focus on the long tail. More room to spread out there. Research combinations of keywords to expand your site into.
Yes, but for me that has never been an issue. Maybe Christmas day itself, and the day after - but that's all. The rest of the month performs great, usually.