I am translating the following text from English to Italian and it is not very clear for me the meanig of the phrase written in bold. Can somebody help me? Thank you in advance.
Twitter is an exceptionally successful platform for many people who are marketing a product or service, but it does require that you build slowly, over time, and connect only with people who are involved in or buying from your industry already. This guaranteed engagement, and because the platform is free, it makes perfect sense.