Most online businesses today have no physical limits to where their customers come from. However, there's a huge difference how relevant a website feels to a visitor based on elements that relate to geolocation.
According to a 2014 Common Sense Advisory report, 75 percent of consumers said they were more likely to purchase goods and services if the corresponding product information is in their native language. Additionally, 87% of consumers who don’t speak and can’t read English won’t even consider buying from an English website.
If you're serving customers from multiple countries with multiple languages or one country with multiple languages (such as India or Belgia), this Playbook is for you.
You can personalize either the whole language based on the visitor's preferred language or just small variations such as "personalize" vs "personalise" if you're going after different markets with the same language.
While the obvious thing to personalize here is language, you can also use the personalize subttle variations in language (checkout how some words are spelled differently in US vs UK).
The preferred language is a good way to capture audiences that might be visiting other countries at any given time or might speak multiple languages while living in another country.
You can combine tactics from the How to personalize content by country to really impact your localization efforts.