Basically you can skip registering a trademark when:

• It really doesn't matter that somebody starts using the same or a similar name.
• It really doesn't matter that you might have to change your name in the future.

Very few businesses would answer yes to either of those questions. But admittedly there are cases when these risks are smaller:

1. You plan to run your business on a very generic domain name that is hard or impossible to trademark because it is a very common word, like "Poker", "Fund" or "Cowboy hats". Risks:
   • With a generic name, your risk of infringing upon another trademark is much smaller but you should still conduct a name similarity check. Domain names that are similar to a registered trademark can later be claimed by the trademark owner.
   • The major risk here is that a competitor starts doing business on a very similar domain name, stealing or deceiving your customers. Funds.com competing with Fund.com. BestPoker.com taking some customers from Poker.com. Etc.
2. Your company will have very few customers and you don't plan to market your company. You are maybe running a holding company or a one man consulting shop.
   
   
3. You are running a local store, restaurant, hotel or service company in a smaller town. Risks:
   • You still have to ensure that you are not infringing another trademark.
   • There is still a risk that somebody will open a similar business under a similar name and start stealing or deceiving your customers.

While a lot of companies take some of the above risks, that doesn't mean it is the smart thing to do. Don't forget that well-managed smaller companies tend to grow into bigger companies. So having a strong name from the start doesn't hurt.