In financial practice, it is used both to find the mean of a distribution, as with derivative prices, and to find a point in the tail of a distribution, as with value at risk (VaR). Both follow the same steps: generate changes in the underlying price with random numbers, calculate values or profits and losses, and aggregate the results.
The error of the estimate shrinks as the number of trials grows, but gaining one more digit of accuracy takes 100 times as many trials. According to a 2002 paper from the Bank of Japan's Institute for Monetary and Economic Studies, practitioners used analytic formulas first for products that could be priced with a formula, and used the Monte Carlo method to value products whose payoff depends on the path and products with many underlyings.