Is dealing on the "Redex" website, which involves purchasing electronic wallets for Bitcoin for $3, with a promise of free transfer and a percentage of profit for bringing in other people to buy the wallet (such as getting $72 for bringing in 62 people), Islamically permissible?

The aforementioned marketing system is not permissible due to its inclusion of gharar (excessive uncertainty) and gambling. The participant pays a fee to open a portfolio, and may either profit from convincing others to buy or lose what they paid. This is gambling. It is clear that the objective is to obtain marketing commissions, as people strive to acquire portfolios to attract subscribers and earn commissions. This is a form of gambling, regardless of whether money is transferred. One must be wary of such schemes. Pyramid and network marketing have previously been prohibited if they stipulate paying fees or purchasing a product.