I am pretty sure most playstation users know who sackboy is, what is your point? 5 years is no where near enough time to become as famous as Mario, Go back to 1981-1986 and ask people who Mario was.
You responded to a comment about showing video game characters to 1,000 random people, so now you are already backpedaling by falling back on PlayStation users.
Not that it really matters. Did you know that Sackboy has essentially been buried? That's my point. Your argument made it sound like it's easy to make a character popular, but the frequency of LBP games had the opposite effect. There hasn't been anything new with Sackboy in a prominent role in years.