US agencies have looked into it and have proposed that it is an 'upranking scheme' for online seller accounts. Packages were labled to contain 'jewelry'.
How it works:
Marketplaces (think amazon) use what are called 'veryfied reviews' to rank and position sellers in different categories.
For a verified review to be written, there has to be a confirmed order, and a package that did go out and was received by the buyer. (Marketplaces track that).
So now you send out a cheapo good from a fake account (email you own), to a valid address, label it as the thing your store tries to flog, when you are not sending out seeds, and make sure to not just stuff it with papershreds, because the customer would maybe try to investigate what that is.
Issue - turns out, people also call the police, when they start to receive seeds in the mail. In Northamerica.
Next time use cheapo erotic underwear, problem solved..
Should already be part of some of those newsstories..
edit: Cheapo erotic underwear and a stone. Marketplaces also check weight (through the postal system).