Flo is her name. She's the spokeswoman for Progressive Auto Insurance.
Flo is the name of a fictional cashier on TV commercials and web banners for Progressive Insurance. She is played by actress and comedienne Stephanie Courtney and has been cited in news articles as having a sizable fan base.
The character has appeared in several commercials since her 2008 debut. She is recognized by her overtly enthusiastic persona, heavy Rockabilly-style makeup, and retro hairstyle which Courtney herself claimed takes about two hours to apply. Referring to her work in The Groundlings, Courtney noted, "Flo could be one of my improv characters, always on and sort of cracked in a weird way." A December 15, 2008 article in Advertising Age said that Flo, "...is a weirdly sincere, post-modern Josephine the Plumber who just really wants to help. She has: The brand is flourishing."