Google Maps will start charging heavy users starting in January.

Web sites and apps will be limited to 25,000 loads of Google Maps API per day and 2,500 loads per day for APIs with Styled Map features. In excess of these limits, users will pay $4 to $10 per 1,000 excess map loads.

"Only the top 0.35 percent of sites will be affected by the charges, and then only if they continue to exceed the usage limit," Google spokeswoman Deanna Yick told TechNewsWorld, according to Ecommerce Times. "By introducing these limits, we are ensuring that Google can continue to offer the Maps API for free to the vast majority of developers for many years to come."

For those who don't want to pay excess loads, they have the option to stay within the loads limit. Google will add a map load tracker on the Google APIs Console and Web sites can use this to keep within the limit.

Non-profit organizations and apps that use disaster relief maps will have no limits but they must first get a Maps API Premier license through the Google Earth Outreach program. Sites that consistently generate a high volume of map loads daily and users of Maps API for Flash will also need to get the license, Google said.

Google Maps counts travel firms and real estate agents among its heavy users. They use the maps to show prospective homebuyers a view of locations they are interested in.