Many wedding venues with banquet facilities have an event manager on staff. They will book the venue for you, assist you with menu planning and usually handle the setup of the tables and chairs as part of their responsibility. Today, many of the wedding venues, also have on staff a wedding coordinator that they include with your wedding package.
The important thing to remember in both cases is that these venue coordinators are employed by the venue. Their responsibilities are to the venue who employs them and is limited to taking care of the venue itself, their food service & staffing and in some cases, depending on the venue, tables and chair set up. They have not worked with you closely over several months getting to know you on a more personal basis, helping you to create your vision and getting to know how you want your day presented. Their services are also limited.
An outside wedding planner is like your general contractor. Beyond the basics, they manage all of the vendors confirming with them prior to the wedding, providing headcounts, coordinating arrival and set up times and to assure that everyone is on task during the event. Your personal wedding planner is there not just to coordinate the day but to set up your décor to create your vision, make sure guests are greeted, assure that the cake cutting and other events of the day are done in a timely manner, music is getting your guests on the dance floor, etc. They are also there to also take care of things that may not go so right – like the wrong flowers being delivered, the cake not delivered on time, getting an emergency keg of beer when you run out, etc. Their services are over and above a venue coordinator’s normal responsibilities.
Your own personal wedding planner also relies on your happiness as their business is built on referrals. The venue coordinator is an employee and their goal is to facilitate the wedding for the venue. Their desire to make your day as special as can be may not be at the same level as your wedding planner who hopes to have you as a lifetime client who will refer their friends and families.