INFORMATION SECURITY TIP: If you suddenly find that someone out there has submitted your email address to a ton mailing lists and attempted to register for things using your email address, don't shrug it off. This is potentially serious if it's being done at scale.
Why would someone do this? Assuming it's not just someone harassing you because they don't like you, the main reason someone would do this is to distract you from important email notifications by flooding your inbox with an avalanche of #spam.
If someone gets into your Amazon or eBay account, they can buy a bunch of stuff, but those orders will generate email notifications to tip you off that something is wrong. If your inbox is indecipherable, you might not see that someone is ordering stuff with your credit cards or moving money around.
If this happens to you, watch all of your e-commerce and financial accounts for unusual activity and change your passwords.
