Should I add chat to my site?

Chat can be helpful for some companies, not used for other companies, and simply a pain for another set. You can try it and see which of these categories you fall into. Most people prefer us to add Facebook Messenger to their site as it's quick and easy to set up, and most people already have it on their phone and know how to use it, so there isn't anything additional to set up or learn. Here are some examples to help you decide if chat makes sense for your company's website:

Service & Retail Sales Companies generally like chat functions on their sites

Service companies with free initial contact often find chat to be useful on their site. For example, mortgage brokers & insurance brokers find some people are more likely to chat them a question than they are pick up the phone and ask their questions that way. Once they have established a rapport on chat then the client is happy to move their communication over to the phone or meet in person as the ice has now been broken. 

Retail companies can reduce their abandoned cart rate and improve their conversion rates as customers who have questions are more likely to ask them by chat than they are by phone or email; and if they can't find an easy to way to ask their questions then they are most likely to leave the site and find another site that answers their questions, or simply not follow through with their purchase at all. Chat on retail sites can help reduce customer service phone calls greatly, as it can become a great way to help many customers at once, something that isn't possible on the phone. If you have multi-tasking customer service reps who get bored when doing phone support, having them on chat support can make their job more fulfilling as they can help multiple customers at the one time - a win for both the customers & the customer service team. 

Business to Business Companies with large projects or long sales pipelines can find that no one ever uses their chat function

Companies where the clients are large and slow to move, are likely to find that their clients don't want a form of instant communication beyond a phone during business hours. The decisions that need to be made by this group are more complex than the promise of instant gratification through onsite chat is likely to provide. Some onsite chat functions on larger company sites are monitored by AI (Artificial Intelligence) most of which are not good at answering complex questions, and generally lead to poor experiences on these sites. Because of this trend, if your clients are used to working with large companies, and perceive your company as also being large and possibly impersonal, then they are unlikely to use the chat function. You could install one and see if anyone uses it, as long as you have someone available to answer questions when they come in (within reason of course), but it may be a extra overhead with little or no benefit to your actual clients.

If you don't give advice for free, don't bother with onsite chat.

Businesses whose product is customer service - such as IT support companies - can find that customers will contact them via chat asking for free support. This can lead to a negative experience on both ends. One way around this issue is to have service subscribers, so only those who are logged in as a verified subscriber can access your chat function.

Also, if you don't like communicating with customers outside of office hours, and you don't have a team that covers a wide range of hours, then this likely isn't going to be as useful for you as it is for more flexible businesses. Some customers are happy to wait for a response, but most use chat to get an instant responce, and if this isn't possible, then offering chat but treating it as email may frustrate customers who are expecting instant answers (such as checking something just before placing their order) when they use chat on a website.