Yeah but if you join today I'll let you in for $750.

You are not doing it justice. MLM is a much better, evolved variant of ponzi scheme compared to the garden variety.

Also, some MLMs sell decent products (I like Pampered Chef) which makes it far from a scam.

MLM is not scamming the customers, it's scamming the "sales agents" by promising them riches most of them won't get due to ponzi nature of the scheme.

Also MLM is, crucially, legal.

IIRC, MLMs are only illegal if they pay commissions based on recruitment of other members.

If an MLM pays commissions on product sales (either directly or through your recruits), then it's perfectly legal.

A tip to anyone thinking of starting an MLM scheme: if you ARE thinking of building an MLM scheme around your product, you NEED an MLM-specialised lawyer to validate that your scheme is legal in each of the jurisdictions you plan to operate in (most likely, US and UK).