I'm not sure if because of popularity or because of the topic/template. You can find imgflip memes on google, so I think certain templates like 'bad luck brian' do well in views because it is popular to search for it. The tags, and the words used in the meme (up to a certain number - goes into Image Description) are indexed, so, that may factor. Also some people, not me currently, share their image on other web sites, maybe their social media pages, so they get more views. For example, if you share it on Reddit, you will likely get hundreds of views, if not thousands. I don't put it on Reddit myself, or any other site. I got a lot of negative comments on Reddit on my memes, I ignored them, but I got tired of it, so I don't share there anymore.