Advertisement insertion techniques are described. In an implementation, a network operator decrypts a stream of content received from a content provider at a first server. The decrypted stream of content is communicated to an advertisement splicer, which locates one or more advertisement insertion points in the decrypted stream of content. One or more advertisements are then inserted in the located one or more advertisement insertion points. The decrypted stream of content having the inserted one or more advertisements to a second server, which encrypts the decrypted stream of content having the inserted one or more advertisements. The encrypted stream of content having the inserted one or more advertisements is emitted to be communicated to one or more clients for output.