OKCupid is one of the most popular dating sites and is free to sign up initially.It works with special algorithms that match users with potential dates.

The app is available in over 80 countries and has over 27 million searchable members.

is one of the biggest dating services in the world.

View Profile Harvard Business School graduate, Mark Brooks, has been an expert in the Internet dating business since 1998.

He is currently the CEO of Courtland Brooks, a consultancy agency for the Internet dating industry, and runs Online Personals

These sites have the broadest appeal and generally the largest membership bases.