1 A loser on facebook
2 Anyone who creates a page or profile on a social networking site with the sole intention of promoting their business or political agenda
3 Anyone who is rather characterless or dull on a social networking site.
"OMG, nobody cares about his plan to restore fiscal whatever... he's such a fabooser!"
"I never should have taught my fabooser mother-in-law how to use facebook... now all of her fabooser church friends are trying to save my eternal soul..."
"I see that your manager is following your twitter... I guess you can't tweet about what a fabooser he is..."