Read this if you want to know what happens when you delete a "mainstream" app that people can't seem to live without.
Why 30 Days? Partially an ode to Morgan Spurlock, who I think was definitely on to something. Thirty days seems like a reasonable length of time to try something new. Mostly because Snapchat gives you 30 days from "deactivating" your account to automatically permanently deleting it.
Why did I do it? The simple answer is that I realized that I was engaging in too much passive sharing of information. Specifically, I saw a friend after a long time and he launched into telling a hilarious story from a couple weeks ago and I interrupted (rude, I know) and said "Oh yeah I saw that on your snap!" and completely ruined his punchline (double rude).
I was noticed I was more productive and I spent fewer mindless minutes on my phone
I missed some of the good stuff - some "you had to be there" moments but mostly I was seeing fewer drunk people embarrass themselves
I realized nobody cares...but really. Both on the receiving and sending side, no one cares. Only a grand total of three people asked me whether I had deleted my Snapchat. Nobody else noticed. Not even my friends who actually sent me direct Snaps on a daily basis.
The long-term effect has been that I care way less about other people's lives.... maybe negatively so but really... absolutely nothing changed. I realize I might not be the best subject for this study but there is no value add or value loss from being on or off of Snapchat. If you're on the fence about deleting your Snapchat because of FOMO rest assured you'll be just fine.
UPDATE: May 2017
I am back on Snapchat, but I can't seem to find any value for it in myself. So back to passively watching stories, but hopefully not ruining anymore punchlines!