What is the fine-grained topic of the following text: With a high mobile penetration rate among the unbanked (7 out of 10 people who don't own a bank account owns a mobile phone) and low usage of financial services among smartphone users in the country (less than 40%), Indonesia is a very attractive market for fintech (financial technology) companies to come in and provide alternative digital banking solutions and other services. Only return the topic.
Potential of Fintech Market in Indonesia