Some reasons to use software to send emails, e.g. with MailChimp:

• email is relatively cheap (low cost)
• email is efficient
• email campaigns offer quick results
• email campaigns can be targeted
• email campaigns can be created easily
• results can be measured easily

Open Rate (OR): % of emails that have been opened

Click Through Rate (CTR): the percentage of receivers that clicks on a link in the email

Click to Open rate (CTOR): percentage of clicks on opened emails: (# clicks / #unique opens) * 100%

Bounce Rate (BR): percentage emails that doesn’t reach it’s recipients and is “bounced” (e.g. because the email address doesn’t exist anymore)