MXroute are offering lifetime accounts for $75

It seems like their 15GB Lifetime plan intentionally has a $1/year fee to ensure you're still around and using the account, as a defense against the plan becoming unsustainable. They don't seem to do that for this 5GB plan... how do they make it sustainable to offer?

I'm not affiliated with mxroute, just a new customer that heard good things.

I am aware that HN is not Ozbargain, but holy moly you can't deny that this is something that "good hackers would find interesting".