When you use Subtraction, you don’t always have to eliminate the
component. There is also what we call “Partial Subtraction.” It is a valid
technique as long as the product or service that remains delivers a new
benefit. To deploy Partial Subtraction, you pick a component and then
eliminate a specific feature of that component. Consider the case of
Twitter, a microblogging application used by hundreds of millions of
people worldwide. By simply restricting each tweet to 140 characters,
Twitter has become a vast digital conversation about what individuals
around the globe are thinking and doing. A Partial Subtraction of
the traditional blog down to 140 characters dramatically increased the
volume of and participation in this Internet phenomenon. How did it
happen?

Twitter founders Noah Glass, Jack Dorsey, and others knew that the
concept was right and that they had a potential hit on their hands. Their
intent was to create a service that allowed people to send text messages
to many friends at one time. Originally, Twitter was supposed to be only
a way for people to easily update their friends on their current status.

But when attempting to build a service with text messaging as
its foundation, the Twitter team ran into challenges. First, texts were
expensive. On top of that, phone companies imposed a limit on the
size of text messages. Any text message of more than 160 characters is
automatically split into two messages. So the first thing that the Twitter
founders did was to place a limit on the number of characters in a
short message service (SMS) text (now called a “tweet”). They Partially
Subtracted text messages by reducing the size to 140. That left room for the sender’s user name and the colon in front of the message. In February 2007, Dorsey wrote, “One could change the world with one hundred and forty characters.”

He was right. Today more than 100 million users subscribe to Twitter. The Twitter website gets more than 400 million unique visitors each month. It has become the global “listening post” when real-time events such as the March 2011 Japanese tsunami and the Egyptian revolution two months earlier are happening. Glass said in an interview, “You know what’s awesome about this thing? It makes you feel like you’re right with that person. It’s a whole emotional impact. You feel like you’re connected.”

Partial Subtraction can create just as much value as the full Subtraction Technique. Partial Subtractions have another advantage. Sometimes you can convince skeptics to do a Partial Subtraction rather than stripping out a component completely to get them on board.