I don't think the government would need (or even want) to limit the number of advertisers for a given product. Its more like the registry that contractors sign up to when they want government contracts. Here's me and here's what I can do.
Having the government control it would at least remove the profit motive behind the advertising service itself. A non-profit could potentially play the same role if having a government do so caused problems.
Having the government control it would at least remove the profit motive behind the advertising service itself. A non-profit could potentially play the same role if having a government do so caused problems.