LetGo, the app-based marketplace for people to sell each other second-hand goods, has nabbed a great deal of its own. Today, the startup announced that it has picked up an extra $500 million in funding from Naspers, the South African e-commerce and media giant, which it plans to use to double down on growth, both in its core second-hand goods sales as well as in newer areas such as the housing listings that it launched last month. The company is not disclosing valuation, although a source close to the business confirmed that it has definitely grown compared to its last funding round, when it raised about $100 million at around a $1 billion valuation.