During August, the number of search queries for my site dropped dramatically from 900/day to 110/day. The website has pagerank 2 and it was starting to make good money. I'm not sure what is the cause of this drop. I've made recently some changes to the website, but I'm not sure whether the sudden drop is caused by the changes or by the link profile. The website contians a blog + e-commerce plugin. During August, I've modified it to use https by default and I've started serving the static content from xxxxxxxxxx.cloudfront .net instead of serving it from a subdomain. I'm using https in order to gain more trust from the customers (this is an online shop). The http version is still available, but each page has the canonical link attribute point to the https version. In the past, I've had some linkbuilding by commenting on other blogs (maybe less than 50 links) and some other links (using about 4 few packs of angela's backlinks). The linkbuilding was done gradually (starting more than 12 months ago) and adding one more angela's backlinks pack last month. There are also a few natural links (built by people discussing about some content or products from my site). I didn't receive any warning message from Google, but I'm worried that this drop could be an automatic penalty. Any ideas on how to handle this drop in search queries ?