Why eBay need a Big Data solution

Q​‌‍‍‍‌‍‍‌‍‌‌‍‍‍‌‍‌‌‌‍​uestions for Discussion Why did eBay need a Big Data solution? What​‌‍‍‍‌‍‍‌‍‌‌‍‍‍‌‍‌‌‌‍​ were the challenges, the proposed solution, and the obtained results​‌‍‍‍‌‍‍‌‍‌‌‍‍‍‌‍‌‌‌‍​?