檔案分享網路儲存廠商之會員制度與服務品質差別策略分析

The Choice of Membership and Service Discrimination of File-Sharing Cloud Storage Service Provider

雲端服務產業不會排除不付費的使用者，但是會以較差的服務品質以及強加的廣告來差別待遇，同時賺取廣告收入。本研究以雲端儲存服務為例，探討面對服務品質需求不同的異質消費者，廠商的最適會費與服務品質策略。本文發現廠商能以非付費會員服務品質降級來提高利潤。如果上、下載服務品質降級相同，稱之對稱混合制，廣告費率低時適合採用會員制，費率高時最好採開放制，費率介於高低之間則適合採用對稱混合制，這種情況下付費、非付費與非使用者三種消費者並存於市場。如果可以採取類似「上傳不設限制、下載非常麻煩」這種非對稱品質降級，在廣告費率夠高的情況下廠商採取非對稱混合制最為有利，否則採取會員制最佳。比較社會福利，不論廣告費率為何，開放制恆為最佳。一般而言，追求自利的廠商只有在禁止非對稱混合制且廣告費率高的時候，才會選擇社會福利最佳的開放制。

The needs for online file-sharing encourages many cloud storage service providers, who host sites withfree basic and paid premium memberships. Assuming ad revenue from on line free users and fee received from paidmembers, this paper considers whether and how aservice providercan raise profits from service discrimination. It is shown that provider can be benefited by discriminating free users with lower file transfer qualities,and choosing the upload/download qualities amounts to a mixed bundling. Per capita adsrevenue (PCAR) is essential in pricing strategy. In case upload/download qualities cannot adjust separately, the site is preferable to offer exclusive free (both/exclusivepaid) membership if PCAR is high (medium/low). In contrary, offering both memberships and prohibiting one of the upload/download services for free users is the most profitable policy while PCAR is high, and exclusive paid membership is the best policy otherwise. Social welfare is always better in exclusive free membership, which is implementable by the provider only if he cannot adjust upload/download services separately.