This classification system has been adopted by various government agencies, trade associations and regulatory boards and not just for statistical analysis.
When working with the Government, spending is done within NAICS code classification. Agencies post contracts bids to any business within a particular NAICS code, such as the Small Business Association (SBA) through System for Award Management (SAM). Other government entities can offer tax incentives to businesses in certain NAICS codes.
Also, companies with business-to-business marketing use NAICS code for market research. This allows businesses to target a particular industry and focus their marketing efforts on those who are looking for their products and services. Gathering NAICS data, businesses can analyze their customers and market effectively.