1. Did your traffic drop, stay the same, or increase post conversion?
It increased, but I'm not sure if it was a result of the https change or not, because I also changed my template/layout/made mobile friendly/etc at the same time, so there was a combination of factors going on all the same week. I figured, gotta make one big change, and the other changes needed doing too, might as well do everything all at once and get it over with.
2. And what was the percentage change either way (up or down)?
It was around 15% - 20% increase, not sure the exact % figure. I went from around 8,000 to 10,000 views a month to around 14,000 to 17,000 views a month (from around 300 views a day before https to around 500 views a day after https).
I didn't do any changes in marketing or promotion or social networking. My process in that remained same as before, so the only change was https, along with mobile friendly template, and moving my layout around to make it easier for visitors to find stuff (changed my navabar - remove the dropdown navabar completely and replaced it with links in a header bar at the top and added a list of my top 500 most visited pages to the sidebar - there are 3,000+ pages). Thus I'm not sure how much of the traffic change was caused by the https change and how much was caused by making my site mobile friendly and making it easier to find pages to visit?
Overall, doing things to improve the site, resulted in improving traffic. I know 300 a day to 500 a day might not be that much, but, I'm a very small niche topic so that's kind of huge when you consider the lack of popularity in my topic to begin with. A site with a more popular topic might find that to be an insignificant increase.