answer the question, "How much money am I making, if any?"
compare your projected performance with actual performance;
compare your performance against industry benchmarks;
use past performance trends to form reasonable forecasts for the future;
show your business growth and financial health over time;
detect any problems regarding sales, margins and expenses within a reasonable time so adjustments may be made to recoup losses or decrease expenses;
provide proof of income if you need a loan or mortgage; and
calculate your income and expenses when completing and submitting your tax return.