There were 18 Web search services before Google, and at least two of them were similar in the way they indexed pages online. I owned an application called Net2Phone in 1996 that allowed people to make online phone calls. That was years before Skype launched and became hugely successful.
I once heard someone claim “There were 17,000 YouTubes before YouTube.” That means that there were 17,000 services that offered some way of uploading and sharing movies online.
In other words; nothing is new, everything is a copy of something, or at least an iteration on a previous idea. The difference between YouTube and the 16,999 companies that failed before it is a combination of several factors. Execution, focus, timing and luck are all part of it. And those factors can be as important as the original idea.
Airbnb is an awesome company, and the idea is brilliant, except that there have been tens, maybe hundreds, of other companies that tried the same thing and failed, or were just less successful. Their value is not in the idea itself, but the perfect timing and execution.
Friendster came before Facebook and Orkut. Remember ICQ and MSN? How about Whatsapp? Geocities and Xoom made it possible to publish a homepage. WordPress was just an improvement on that original idea. Just like Tumblr is the new WordPress and Squarespace is the new Tumblr.
The goal isn’t to reinvent the wheel or come up with an idea that no one else has ever come up with. You can be very successful just taking something that someone else failed at and do a better version, at a better time.
If it worked for YouTube, Google, Facebook, Whatsapp, AirBnB and Skype, it could work for you.