There are 2 ways by which a community owner can invite members to be a part of their community.
Community owner can invite members:
At the time of creating the community.
After creating the community.
How do I invite members to my community after creating a community?
Click on the particular community to which you want to invite members.
on the left side, you will see an option to “Invite and Promote”
Click on “Invite and Promote” and choose how do you want to invite members.
You can invite members to your community through Facebook, Google+ and Emails.
How do I invite members to my community through Social Media?
There are two ways to invite members to your community via Social Media.
Facebook
Google+
Choose any of the options from Facebook and Google+
Add your contacts and type a custom message.
Hit the SEND button! Your contacts will now receive the message on their Social Media accounts.
How do I invite members to my community through Emails?
Community owners can invite members to join their community by sending them emails.
Click on the CREATE CAMPAIGN button and choose the imported contacts to whom you want to send an invite to.
If you want to add a new contact, you can add by clicking on the Add new contact button.
Add a catchy subject line that will attract your recipients and make them open the email.
Add a custom message on what is the objective of your community and why they should be a part of your community.
You can preview how your email will look by clicking the “Live Preview” button.
When you are ok with your email template, click the “Send Mail” button.