Official Gmail Blog: Introducing Gmail Labs
When google introduced Gmail labs, by doing this, google not only making its reliable but also user friendly.
when google design a new feature to its services, it firstly introduce it in google labs.
a part of google lab is gmail lab
what happen is that google let people to use this newly designed features and collected thier feedback and improve thier design by keeping their on feedback
this feature will be may be available to you by default when this feature get graduated from this labs.
to support discussion between the test user and google engineers, google uses google groups .
which new feature they should design is also bought to thier ideas from the feedback user of the google products provide.