My site is a large web photo gallery structured hierarchically by region.
I read in this forum a few months ago that Google was going to make changes to their ranking algorythm to penalise companies which pay people to create a large number of pages with low quality content but full of ads.
My site does not belong into this category, as I create all content myself and it's primarily photos, but it seems that traffic dropped noticeably at some point around January-February.
Another issue is this general trend in falling Alexa rank (my site was around 90000 about three years ago and it's now around 150000).
The dropping has not been continuos, it was rather a series abrupt drops, one a few years ago and the most recent one in January-February this year.
My site's content type and structure has not changed over this time (but I do add new content all the time), so these traffic drops *perhaps* can be attributed to Google. This is of course just a guess.
I'm wondering if I need to modify something on the site, i.e. optimise it in some way for search engines.