I normally go to playback locations, this is where I can back track and see how my video was posted somewhere. I'm always curious how I get sudden view spikes and it's normally when it's shared somewhere.
I went into playback locations and one of them was embedly.com which doesn't really help much....I wonder if google analytics gives more details.
There are some sites where it's hard to find where it was shared. I normally go to custom date range and put it to the day before and the day of the views I'm interested in when there is a spike. This allows me to see what video has an unusual amount of views. Then I either go to the site and just scroll down or I have even used a Google search using the website name then either my channel name or something from the description. Here's an example of one where I just went to the site listed in playback locations and did a quick search for Dalmatian ollie. This embedded view ended up spreading my video pretty quickly, it got about 30k views in the next couple days after this site shared it on Facebook. The cool thing is I shared my video with the site the day before, so I found out that they actually take suggestions when videos are good. They have posted a couple of my dog videos and each one has a lot more views than most of my other ones.
Once I find how they used it, I look at other stuff they share to find a theme. Then I find something from my library and fire away.