If you have and use a twitter account, you may have encountered this feature: based on your contact details and your following history, Twitter algorithms suggest you 5 people to follow.
The question Tudor Galoș addressed at MK4IT is “Why 5? Why not 7 or 30?”.
The answer is ridiculously simple: there is an average of 5 things we can remember. Twitter wants you to have a pleasant experience and it values not only your activity as an active user but as a follower too.
The point is that you have to base your product on research, test it and correlate it with the long term objectives.
By the way, you can follow us on twitter.