The nickname Flo Ripoff stems from Flo-Rida's ridiculous usage of samples of other songs in his own productions. Basically, Flo-Rida is known to rip off other artists and steal their choruses and hooks.
The most atrocious examples of Flo Ripoff are "Right Round" and "Sugar". "Right Round" samples the chorus from the Dead or Alive 1984 hit "You Spin Me Round" and "Sugar" the song's chorus is a blatant ripoff of Eiffel 65's "Blue (Da Ba Dee)".
Darnell: Hey man, what are you listening to?
Justin: It's Flo Rida's "Right Round" this stuff gets the shorties poppin at the club! Have you heard of Flo Rida? This dude goes hard!
Darnell: Yeah, more like Flo Ripoff...
Justin: Don't hate bro, Flo Rida's joints be bumpin!
Darnell: Yeah right, at the expense of jacking the hooks of other songs. Flo Ripoff is corny as hell.