1. Brick or Potato
Creators: Justin and Robbie Holt
Flowers too cliché? A card too personal? Instead, try sending your friends a personalized message... scrawled across a brick or a potato. This service, which promises to be "completely hilarious" and "completely anonymous" launched late last year. In just one month, the Holt brothers earned £11,000 shipping their atypical objects.
3. Pet Rock
Creator: Gary Dahl
Advertised as "the only pet that will never run away," the Pet Rock took America by storm in 1975, generating over £10 million within the first six months and making creator Gary Dahl an overnight millionaire. The pet rock is truly the gag gift that kept on giving.
5. Lucky Break Wishbone
Creator: Ken Ahroni
Created back in 1999, these plastic wishbones are Ken Ahroni's deceptively simple solution to the problem of who gets to crack the wishbone on Christmas day in a family of more than two people. His answer: everyone. Today, Lucky Break Wishbones generates approximately £1.7 million per year.
7. I Can Has Cheezburger
Creator: Eric Nagawa and Kari Unebasami
It's been said that the internet is only good for finding pictures of cats. You can blame Eric Nagawa and Kari Unebasami for that. Apparently the creators of icanhas.cheezburger.com spiralled into a seventy-three minute laughing fit after creating a photo of a fat cat with a nonsensical slogan. Their website now generates over 8,000 fan entries daily and has enjoyed profits in the vicinity of £1.5 million.
9. Yellow Smiley Faces
Creator: Harvey Ball
Created in 1963, Harvey Ball's world-famous yellow smiley face was originally a logo for a client of his PR company. Sadly, this success story isn't Ball's, because he was paid only $45 (approximately £32) for his work, and in 1971 the brothers Bernard and Murray Spain were able to gain the copyright by adding the slogan "Have a Happy Day" to the iconic image. By the end of the year they'd sold more than 50 million novelty items and their Hallmark card shop had expanded into a chain.