Burbn had attracted a core following of users, but was not exactly taking off. Upon further evaluation the founders noticed that photo uploading was the strongest and most used feature. Instantly, they cut all other features, kept with uploading photos and moved forward with the newly minted Instagram.
Systrom resisted being all things to all people and in the end sold his 15 month old company for $1 billion. Think about that for a second. By removing most of his product and getting down to the essential, he drastically enhanced its value.