Three-quarters of first-time homebuyers were renters before buying
Realtor.com, Zillow.com, Trulia.com, Homes.com also among leading sites
Realtor.com: Half of homes on list are in Florida, Arizona
Hitwise: AOL Real Estate among 'fastest moving' sites
Company expects $198M total revenue in 2010
HUD.gov, HomeAway.com rejoin list, too
Hitwise: Reply.com, Move.com and WhiteFence.com rise in December