Do I need more than one dedicated IP address for my VPS?

The quick answer is no. One dedicated IP address for your VPS works for:

Multiple SSL certificates. Your server supports Server Name Indication (SNI), which means you don't need one dedicated IP address for each SSL certificate on the server.
Search engine optimization (SEO). A single IP address doesn't affect the SEO for any of the websites on your server. Just make sure each site has its own directory on the server.
Site previews. Your customers can preview their websites using the same IP address as long as you've configured cPanel or Plesk properly.

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