Successfactors internet rating systems

Every selfrespecting internet service has a rating system in place. On YouTube you can rank their videos and Ebay you can rank sellers and buyers. Rating is a very powerful crowdsourcing tool to help users to decide. But not every rating system is very succesful. In this article I would like to get into these successfactors.

I start with two examples of rating systems; a successful and unsuccessful one. One of the most successful rating systems is employed by Ebay. Ebay lets their users rate both buyers and sellers. It is successful because Ebay users actually use this information to decide if they want to buy from a seller or not. Therefor it is essential for sellers to have a high rating to be successful on Ebay. Due to this interaction the quality of sellers is very predictable on Ebay.
To me the rating system of YouTube is a complete failure. You can find lots of videos with the number of views in the hunderd of thousands but with only a couple of votes. YouTube users cannot really rely on the rating to determine if they wanna watch a video or not. If less <1% of the users vote the rating is not really representative for the group.

So what does determine the success of a good rating system? I identified three of them:

Sense of purpose to vote

Rating makes only sense when the rating has a clear purpose in the context of the users. If you take the YouTube example the reason people are not voting because there is no real use to vote. The rating on a video does not tell the user anything about the relevancy of video for him or her. The person giving a rating could be watching the video for an entirely different reason than another person. You cannot compare these ratings.

Sense of purpose of the vote

In line with the previous successfactor the rating has to have a real need for the user. Take for example the seller/buyer rating on Ebay. This rating has a clear goal for users. They can use the rating to determine if they want to buy or sell with a particular person.
Without a clear sense of purpose of the vote users will not use the rating system because it has simply no use.

What’s in it for me?

To entice a user to vote you need to be able to answer the question “what’s in it for him or her?”. Users do not rate just because they can. They rate because it gives them or others benefits as with the Ebay example.
You see that on YouTube rating is not really used because there is no point to use it. It does help you find new videos or determine if a video is worth watching.


Any rating system to be successful should take into account these three successfactors. A unsuccessful rating system is even worse than having no rating system. It confuses users and sets wrong expectations leading to disappointment.
The internet is full of rating systems and every selfrespecting internet site has some form of rating system. But most of them are pretty useless.
Examples of rating systems I like are:

  • Ebay – their buyer/seller system
  • – recommend songs based on your ratings