Other companies give access to the company-internal information to the cleaning company. Many exchange business critical information by using a phone company.

Other companies give access to the company-internal information to the cleaning company. Many exchange business critical information by using a phone company. When self-hosting you have to care about your service-level agreements and trouble solving. If you rely on it you quickly need a growing IT/operations team. sometimes it's cheaper to pay somebody how is specialized on this. Of course one has to evaluate the company, with the ones which make money from selling information (to advertisers) I'd be more critical, but that's a matter of evaluation of options.