Marvel| Ant-Man Mini Billboards

To build hype for their upcoming movie, the marketing team behind Ant-Man placed tiny billboards in Australian cities.

Naturally, people reacted in the only way you would expect in 2015 when seeing something out of the ordinary, they posted pictures of it on social media. This is a genius way to get people talking about your brand, without asking them to.

Airbnb| #treehousetuesdays

A great way to get people excited about your brand is to offer them the chance to experience something unique. With #treehousetuesday, Airbnb features photos of actual listings in their service that allow you to spend the night in a real-life tree house. Judging from the engagement on this photo, I'd say it's working well for them. 

Head any direction from this Washington state treehouse, and you’ll find something extraordinary to explore. A five-mile stroll north gets you to quaint village-within-the-city Fairhaven, find the majestic Skagit River Valley 20 minutes south, head east for the waterfalls of the North Cascades, or venture west to board a ferry to the San Juan Islands. #TreehouseTuesday Click the link in our bio to check out this listing's nature-inspired design. Photo cred: @moneal

A photo posted by Airbnb (@airbnb) on Apr 26, 2016 at 5:19pm PDT

Offbeat Bride| Altar Your Thinking

Offbeat Bride is a wedding website that brings high-quality content curation to social media -- pinning their own content and other useful content for their followers to explore.

Their Pinterest account is a must-follow for brides-to-be, providing ideas for engagement photos, wedding venues, dresses, and much more, along with some of the most creative wedding ideas you've ever seen.

While more of an every practice than a campaign, their sharing attracts a great deal of fan attention and interaction. 

Samsung| Celebrity Selfie

Who could forget the star-studded selfie from the 2014 Oscars that received 1 million retweets in 45 minutes? While this isn't technically a campaign, it was a great accidental social marketing by Samsung.