Google is to start charging customers for heavy use of its Google Maps API.

The service, which is popular with hotel review sites, retailers and restaurants to help direct customers to their location, will cost from $4 (£2.50) for every 1,000 hits from January 1 2012.

However, a report by technology news site dailyconvo.com estimates this will only impact 0.35% of all users because the majority of sites use the API less than the set parameters.

Thor Mitchell, product manager at Google Maps API, said the introduction of a charge was to ensure the company can fund its progression. “We understand that the introduction of these limits may be concerning,” he said. “However, with the continued growth in adoption of the Maps API, we need to secure its long-term future by ensuring that even when used by the highest volume for-profit sites, the service remains viable.”

He added: “By introducing these limits, we are ensuring that Google can continue to offer the Maps API free of charge to the vast majority of developers for many years to come.”