I'm wondering which languages are most popular with internet users in countries around the world.
My initial research found browser usage statistics by country, but nothing about proportional language preference.
Are there any such resources?
I would suggest looking at the country itself and researching its most commonly spoken languages. I would advise against using the country's official language(s) because they are not always accurate to the population.
Here's a great resource to get you started: World Factbook