Mark Spain Real Estate, founded in 1996, is a privately held residential real estate brokerage headquartered in Alpharetta, GA. The company offers traditional agent-assisted services alongside a Guaranteed Offer cash program designed for quick home sales. As of 2024–2025, it has surpassed $18 billion in lifetime sales and employs over 500 staff across multiple states. Notable milestones include becoming independent from Keller Williams in 2016, being named the top real estate team in the US by Wall Street Journal multiple times, and earning repeated awards from Inc. 5000 and Atlanta business publications.