Well, they did not say whose lifetime.
I've learned my lessons when I got my lifetime deals that scammed me:
* archhosting -- lasted 2 years before it folded
* zoolz -- changed their mind 3 years after their lifetime deal, and forced everyone to go to their paid plan.
Small discussion (8 points, 4 days ago, 2 comments) https://news.ycombinator.com/item?id=42657505
Is that legal? Surely they can terminate for convenience going forward if that was in the ToS, but they can't terminate a right accrued as of the terminate date?
My rule: when buying a 'lifetime' service, assume that equals 10 years and weigh the cost accordingly. A lifetime Nebula subscription is $300, so $30/year. Is that reasonable to you for the service? Then go for it, and be pleasantly surprised if it lasts more then 10 years.