To add the adds to a torrent file for example, Peer Matrix would have to alter the content, a process known in Bittorrent circles as "Poisoning" because it is often used by greifers and anti piracy groups to wreck a file in a given "swarm" of users. Because of this, most clients filter out and prevent poisoning so your ads would not go anywhere.

On other file shareing P2P services, the file that is being transfered is hashed (put through a mathamatical algorithm that comes up with a standard sized string of characters). A file can only have one hash value, but a hash value can represent several possible files. The file's hash is often automatically checked after downloading. If they don't match the file is thrown away. sometimes they match several diffrent diffrent hashes. then these programs will throw away the content downloaded and block the source.Eihter way noads will get through

Then there is the problem of turning off users who weren't expecting an ad and downloaded content they did not expect an ad. Also there is the issue of you profiting of another persons intelectual property. It could be legally argued that you are a pirate,while the person who posteditmayonlybe a copyright infringer.

IMHO.... DO NOT USE.