The answer depends on your business goals and what you are trying to accomplish by doing so. According to GoDaddy, there are several reasons to have more than one domain name such as keeping your competition from registering a similar domain name, promoting the different locations you serve, creating distinct advertising strategies reaching different target markets, capturing common misspellings of your domain name, and protecting your brand and online identity.
If you set up all of your domain names to point to the same website, search engines will recognize that multiple URLs have duplicate website content. This is a very bad SEO practice and will hurt your site's SEO. Much of the content will likely not be indexed which will ultimately dilute your site's search engine ranking. Part of our ongoing service is to help our customers set up their domain names for best-practice SEO. If you have doubts about your current setup, contact our team for assistance.