When I first started my brand Average Black Girl the www.AverageBlackGirl.com was taken. It was not being used but there is a whole game of people buying up domain names, holding them and waiting for you to come up with an idea and then charge a premium for you to buy it. I tried to buy it from them but they did not respond. The person ended up not renewing payment and I was notified by my domain host that a similar domain was available would I want it. Now I own averageblackgirl.com and averageblackgirl.org and they both point to my site. Now I am going to list why having multiple domains is important and something you should look into as your business grows.
As you grow globally, country specific domains tend to rank on certain search engines depending on the geography. You may want to invest into a country specific domain as you grow and immerge into certain regions.
People mispell companies all the time, especially when typing in a hurry. I noticed one day that I misspelled walmart looking for an item and it lead me straight to the store. I then spent another 5 minutes coming up with different misspellings and learned that they have bought a number of misspellings to ensure people drive to their site. Another popular site that does that is facebook. As you grow you may want to buy the misspelings of your domain. If not, someone else can buy them and have them direct your mispellings to their site.
You may want to have different landing pages or a course page associated with your business. For example, I may want to purchase learnaverageblackgirl.com or something like that.
Restricting Competitors + Protecting Brand
If you do not buy it, you are allowing your competitors to buy your .org or .net and start a business using the same name. That could lead to brand confusion and missing potential clients. Even if a competitor does not name an entire site your name they can still have that domain redirect to your site. For example, I could have bout walmrt.com and have it direct to me and have that drive tons of traffic, if they did not buy that domain.
Rich key word domains can enhance your ability of being found. For example, I may want to purchase Smart Black Girl or Wealthy Black Girl or Smart Women Can because those words are highly searchable.