The purpose of the CMA is to help determine the current market value as affected by active and sold listings (typically within a 2-mile radius of the subject and with similar characteristics), supply, demand, local economic conditions, mortgage rates, forecasts, etc. This differs from a bank appraisal for the purpose of a loan (which is primarily based on the most recent comparable sales in the immediate area allowing the lender, based on regulations to confidently award a mortgage loan to the borrower) and a tax appraisal (based on the historical values of the property factoring in most recent sales price as well as overall county value appreciation vs depreciation of local market). The county formula is a bit tricky.
I pull in data from multiple sources, including but not limited to: the MLS (for detailed descriptions, photos, market time, sales history, updates, upgrades and more), county records for property tax information, ownership, fees and liens, local lending and economic forecasts, and happenings nationally and internationally.
For a seller, getting the list price right the first time is key to getting the highest/best sales price. Based on all of the above, the correct list price will also help determine what additional terms will be most important to include in the contract in order to successfully close the transaction.
For a buyer, the CMA will give confidence in the price and terms they offer.