Best Way to Add 500 new users

Hi Nancy , thanks for sharing your question! There are a few pointers I can share from my experience.

• Raise awareness of and build excitement around your community. You can do this through your existing channels of communication, whether it be your website, blog, newsletters, or meetings. Let people know the benefits and highlight activity happening in the community. 
• Create a friendly welcome email. Prior to inviting users, customize your Welcome Email in Admin > Settings. This will be the first communication members will receive after they join the community, so it's an opportunity to greet them, provide tips for getting started, and links to important posts or areas in your community.
• When adding users, customize your email invitation. When you add users into the system, check the option to send them an email invitation. Enter a subject line and message that resonates with your audience. The invitation link appears at the bottom of the message. Encourage them to join by clicking the link.
• Invite in batches. You can start by inviting a smaller set of people and solicit their feedback on the process. Based on this feedback you can adjust your invitation message, welcome message and other areas if needed before inviting the next batch.
• Cultivate community advocates. If you have people who are particularly excited or enthusiastic about the community, you can invite them into the community first. They can help jumpstart conversations and be a support to new members. 

I hope that helps! Please let us know if we can provide any assistance in your on-boarding process.