With the popularity of the internet business today, it is very common for a company to register domain names in a bulk. If a company has a website on keyword research tools then they could buy domains like keywordresearch.com, keywordtools.com, researchkeywords.com, etc. It helps the company to grow more widely. If a companies has branches of categories then multiple domain names will enable them to target each niche in the market with a specific domain. If they plan to target different countries han it is a good idea to have bulk domains each representing one country. Also you can get discounts through bulk domain registrations. A site which costs $10 for a domain can give a domain for just $1 if bulk registrations are made.