Example: 87% of statistics are made up on the spot.
A "citation needed" tag is a request for another editor to verify a statement: a form of communication between members of a collaborative editing community. It is never, in itself, an "improvement" of an article. Though readers may be alerted by a "citation needed" that a particular statement is not supported, many readers don't fully understand the community's processes. Not all tags get addressed in a timely manner, staying in place for months or years, forming an ever —this itself can be a problem. Best practice recommends the following:
Before adding a tag, at least consider the following alternatives, one of which may prove much more constructive:
At the moment, there are over 321,345 articles with "Citation needed" statements. You can browse the whole list of these articles at Category:All articles with unsourced statements.