What is the ruling on dealing with "Quest International Limited," a company founded in 1998 and headquartered in Hong Kong, which uses direct selling and binary tree marketing for its various real products (watches, coins, alternative medicine products, communications, tourist trips)?

There is no objection to subscribing to the company to benefit from its legitimate services under Sharia (definition)-compliant controls, such as working as a broker to attract customers or as an agent to sell and market products for a specified commission. As for multi-level marketing (pyramid scheme), it is forbidden. The doors to lawful earnings are many, and methods of legitimate gain are available, far from forbidden transactions based on deception, fraud, and unjustly consuming people's wealth.