According to Anti-Phishing Working Group, there were 119,000 fraudulent websites out there that were just aiming to steal your information. So be very wary of sites you're not used to or that look unusual.
So how do you make it stop? Here are some suggestions:
- Always unclick the boxes allowing companies to send you offers
- Give companies an address apart from your main account - for example, set up a second Gmail, Yahoo, etc. account just for companies you do business with
- Use a service such as www.unroll.me to manage subscriptions
More unsubcribe options can be found on PC Mag's website.