Crossposting

Crossposting is the act of posting the same message to multiple information channels (forums, mailing lists, or newsgroups) in such a way that reading software can relate copies of this message on different information channels. Thus reading software is showing this message only once. This is distinct from multiposting, where copies of the message cannot be related.

Crossposting is advantageous to the poster because it increases a number of answers. Suppose that a message does not belong to a distinct topic, and crossposting is not allowed. It may be that the poster sends the message to some channel, but some reader expects it on a different channel and will never receive it.

Crossposting and off-topic could be considered spamming. The more channels receive a message, the less is the probability that it is on-topic, so excessive crossposting is generally considered bad practice. In the extreme case, if all messages were crossposted to every unmoderated channel, then every unmoderated channel would look exactly the same. A crossposter can minimize this problem by specifying that all responses be directed to a single channel.