Bitcoin as an retirement plan, bitcoin to secure the future of your kids, and now bitcoin as a wedding gift. Whether or not bitcoin replaces cash in future, it looks like the trend of gifting bitcoin instead of cash at weddings is definitely going to catch up and more wedding registeries would be adding bitcoin as a gifting option.
People who are not into bitcoin might not appreciate getting a volatile currency as a gift, and might never use it, thus adding it to the list of lost coins, but I think people who are already using bitcoin or would most probably use it in future then bitcoin instead of cash is the apt wedding gift for them.
http://www.marketwatch.com/story/would-you-give-bitcoin-as-a-wedding-gift-2017-06-27
I just suggested this to a friend who is getting married recently and he loved the idea.