Taking a site from 1000 uniques daily to 100000 uniques daily

I currently run http://www.snapchatmap.com which is averaging around 1200 unique visitors per day. This is by far the most popular website I have ever created and I believe it can become even bigger.
My visitors have plateaued recently and I would like to hear peoples opinions about how to take it to the next level so that I can start making money from it. My current ideas are:

More SEO
Paid advertising (which platform?)
Trying to make some kind of viral advert…

Taking a site from 1000 uniques daily to 100000 uniques daily

See original post by jimmyt200388