Social media platforms moderate content in many ways, balancing the desire of content
providers to be seen and trusted with consumers’ desire to see and have certified only the content
that they value. Content moderation by platforms has come under regulatory scrutiny. We introduce
an abstract model of content moderation for sale, where a platform can channel attention in two
ways: direct steering that makes content visible to consumers and certification that controls what
consumers know about the content before further engagement. The platform optimally price discriminates
with both steering and certification, with content from higher willingness-to-pay providers enjoying
higher certification and more views. The platform increases profits by cross-subsidizing content
from low willingness-to-pay providers that appeals to consumers with higher willingness-to-pay
content that does not. This cross-subsidization can also benefit consumers by making content more
diverse, suggesting that regulation pushing for accurate certification may be harmful. We identify
cases where imperfect certification might be most likely to occur and when forcing higher accuracy
would be beneficial.