I know switching to SSL/TLS is something that's becoming more discussed lately. I thought I'd share my experience with migrating to a secure setup. I'm not the world's expert or anything but maybe this info can be of use to some of you.
I switched to SSL/TLS about two months ago. There was an initial revenue dip. This lasted about two weeks but surprisingly after that revenues came back really strong. I say surprisingly because most people I asked told me revenue would nosedive and I would regret the switch. I can say I absolutely do not regret it. I actually think it was a great decision because it seems like the actual QUALITY of the ads served has gone way way up as well since the switch. Not sure if that is related but I don't hate it.
I think the important thing is to configure it all correctly. Make sure your sovrn ad tags use https - use the new compliant tags if yours are older than like a year old. Just go into your tags and pull the newer code and replace your ad tags on your site. If you don't understand how to do that I'd rec contacting your rep and they can walk you through it.
Then go make sure your actual server settings force all components of your site to https just to make sure you are padlocked on every page. This prevents 99.9% of the annoying 'omg not secure mixed content angry meeping' errors. Depending on your website/hosting setup you can do this via htaccess or if you use Wordpress you can add a couple of lines to the wp-config file. You can google 'force https' or 'force ssl' and read up to decide the best solution for you - some methods are more MacGyver-ish than others so explore all your options.
It's def helped with SEO on google. If you use Google Webmaster tools get in there as soon as you move to secure and switch your site over to https, resubmit your https sitemap, and resubmit for a fresh crawl. That should get things indexed with your new secure url a little faster.
If you use a cache system make sure you configure it to work with SSL/TLS if you can - that was a tricky one for me and I dealt with some performance issues due to not thinking about my site cache system (so rookie I know). I mean obviously if your site is loading slow you're not going to make a lot of revenue, so that's something to look into.
I can't remember any more right now beyond just making sure you monitor things really tight for the first month and course correct as needed, and be patient about revenue bouncing back. I'd love to read any tips anyone else has!