2) What is the difference betwen a referal system and a pyramid scheme?

In a referral system, participants are often rewarded for bringing in new customers or users. The key distinction from a pyramid scheme is that a legitimate referral program involves the sale of actual products or services, and the rewards are based on genuine transactions.

In contrast, pyramid schemes primarily focus on recruiting others into the scheme with no real underlying business or product.

3)Charging a fee to use services on a social media platform is it a pyramid scheme?

Charging a fee to use services provided on a social media platform itself doesn't classify it as a pyramid scheme. However, the legitimacy of such a business model would depend on factors like the services provided, transparency, and whether users are genuinely receiving value for the fee.