BARCELONA, Spain (AP) — Here’s the rub for companies: A good part of the key markets they serve already own smartphones and use them to connect various Internet services. How do you grow from there?

Services from Facebook to Firefox are looking to emerging markets for the next few billion people. They are not only targeting the obvious high-population countries such as India and China, but also see potential in Latin America, Africa and just about everywhere beyond the U.S., Canada, western Europe and a few Asian nations.