Stickers are a common promotional item that has been used for everything from political campaigns, cause advertising, supporting local football teams etc. They work as they are cost-effective on large scale, easy to ship and allow the recipient to show their support for their team, cause etc.
They come in many forms for different uses; like outdoors use, car bumpers, laptops etc. They also come made of different materials like epoxy domes, metallic, reflective and waterproof materials.
While marketers often use them for brand awareness, there are much more effective ways to use promotional stickers. A good case study is what Evernote did when they heard customers complain about employees using laptops in meetings.
Their response was to produce a laptop sticker that said –
“I’m not being rude. I’m taking notes in Evernote”
Their customers then became mini billboards for Evernote from meeting to meeting.
Notice when you buy an Apple product you get an Apple sticker in the box, these guys know what they are doing when it comes to leveraging loyal supporters.