SG&A expenses are an important benchmark as to the company's break-even point. Regardless of sales, a business needs to cover this mostly fixed overhead cost before it can begin to turn a profit, so understanding SG&A is important for management to understand.SG&A expense and its revenue ratio play a key role in explaining company profitability. Companies and investors often use a ratio that compares SG&A expense with sales revenue as one way to measure a company's financial health. If the ratio is too high or increases with time, this may indicate difficulties sustaining profitability.After mergers or in times of financial hardship, SG&A expense is the first area that management would examine to cut costs without impacting manufacturing or sales. At the same time, companies need to act wisely in making these decisions. Aggressive cuts in spending may yield short-term improvements while resulting in a long-term decline in revenue.SG&A expense ratios vary widely by industry and should therefore only be used in comparison with like industries. Pharmaceutical and healthcare have some of the highest SG&A expenses as a percent of revenue, while energy typically has a much lower ratio.