If you are on your own right now, don't do it yet. As one man team, you'd probably only have an hour a day to deal with it and people will find it annoying,as they tend to expect quick response when it comes to chat. Last year I was checking on this product(saas of sorts).It turns out it's just one guy behind it,who does it all. He had a calendar plugin on his website,where you can select a meeting time based on his availability.Worked like a charm. If your product is highly transactional,you may want a different approach then.