How do you bring it out to be actually bumping the threads based on providing their services or are purposely doing it just for the sake of such threads being removed due to competition? What measures are taken when people are found who do it purposely? Are these guys banned or just warned to stop what they're doing?
Whoever is caught bumping their services, is perma-banned. If a competition is staging the bumping, there's a fair chance it works out well, and the only thing the thread starter who could have been potentially banned is that he'll have to create a thread in meta about it. There's no real way to, at least for regular users to figure out who is behind the thread bumping scenario.