CoStar may soon have some stiff competition, and not in the real estate data and analytics space.

Apartment List, which offers a similar service to CoStar’s Apartments.com, has secured $50M in its latest Series C fundraiser led by Passport Capital founder John Burbank, and is now the fastest-growing rental marketplace in the U.S.

Apartment List takes a personalized approach to the rental process by allowing tenants to find a new home based on a set of preferences. Renters are then sent listings based on their preferred amenities, and are informed of any price changes in real time.

Apartment List has secured several notable partnerships since its founding to aid in its growth efforts, including Facebook Marketplace, Realtor.com, Homes.com and Doorsteps.com.

“Renters deserve the same personalized, seamless, white-glove experience that buyers get. We’re innovating our marketplace and scaling our business to help people make better, smarter decisions about where they live and we won't stop until we've won this market. This investment brings us one step closer to that goal,”Apartment List co-founder and CEO John Kobs said in a statement.

The company has raised a total of $110M to date and over the last 12 months has increased the number of properties on its platform by 50%. The site now hosts close to 4 million listings, or the equivalent of 10% of U.S. rentals on the market.