It depends on your requirement! For example, at Crisp, we have different plans. We offer a free live chat software that you can install on your website with no limitations! You can have two agents to answer your website visitors in real time. It comes with a web app and mobile apps to let you answer your customers even if you're not in front of your desk. Most of the other live chat service providers such as Tidio, Zendesk (Zopim), LiveAgent, Tawk, Hubspot or Olark, are billing per agent, from the start. Meaning the more you add agents, the more you'll pay. At Crisp, we believe that you shouldn't pay more to improve the quality of your customer service through live chat. That's why we have a billing system that relies on inboxes. Our unlimited plan comes with a flat price, nothing more.