This site did not show evidence of storing passwords in plaintext.
This site does allow secured connections (https)
This site did show a clear way to unsubscribe from their emails
This site does verify your email address.
Below is a sample of the emails you can expect to receive when signed up to Common Impact.
Thank you for signing up for email communications from Common Impact. We look forward to keeping in touch, but you can unsubscribe at any time by clicking "unsubscribe" at the bottom of in any one of our emails.