Below is a list of 10 silly inventions and business ideas that made their inventors rich:

10. Pet Rock - The very idea of selling rocks is dumb. However, in 1975 , Gary Dahl was able to make millions from it. He envisioned it as the perfect pet, as it did not need to be fed, walked, bathed, or groomed; and would not die, become sick, or be disobedient.

9. iFart App - This app was launched by Joel Comm in 2008 and was a huge seller in the Apple App Store. To make it work, you press a button to let loose sounds with names like "Jack the Ripper," "Howard the Duck" and "Bubbler."

8. Wacky Wall Walker - Ken Hakuta should be thankful to his mother for giving him the business idea that generated millions. The toy was sent to him by his mother from China. When it is thrown onto the wall, it slowly walks down. Ken bought some rights to it and began selling it in Washington, and it soon caught on.

7. Slinky - Invented by naval engineer Richard James in 1943, it was an instant hit and soon became a nationwide craze. He came up with the idea when he was trying to develop new springs and accidentally knocked one from a shelf, and watched as the spring "stepped" in a series of arcs to a stack of books, to a tabletop, and to the floor, where it re-coiled itself and stood upright.

6. Snuggie - This sleeved blanket bathrobe product has been the topic of much ridicule, but has made millions. It grew in popularity after it was marketed through infomercials.

5. Beanie Babies - A stuffed animallaunched in 1993 by Ty Warner that used plastic pellets ("beans") instead of conventional stuffing. This made the animals have a flexible feel, and appear more realistic. A large collectible market also emerged for the product, with some selling for thousands of dollars on eBay.

4. Doggles - Having dogs wear goggles sounds like a stupid idea. However, the man behind the idea was confident about it. The purpose of this product was to protect the dog's eyes from infections, debris etc. The product has been sold in large numbers and has brought in millions for the company.

3. The Singing FishThis device had been created by a toy company in Texas. The owners had never imagined the success and profits the product would bring. The only feature the fish had was that it was able to sing. It has been reported that one million units were sold in 2000 alone.

2. Furby - This plush toy had a lot of fur on it. It was cute, innocent looking and something everyone wanted to have. This is the reason for which adults and children equally liked this product which sold millions.

1. Billy Bob Teeth - This 1990s novelty product makes anybody look like a redneck. The company has sold over 15 million of them and has expanded to have 250 other gag items.