Some of you put customer comment cards on your tables and ask that guests fill them out and let you know how you're doing.  I could put money on the fact that you receive more complaints on those cards than praise.  Unless someone was given absolutely outstanding service or the food was just phenomenally prepared, your guests aren't going to take the time to tell you some of the things you really should know.  They might tell you that the potatoes were cold or the salad was wilted, but do they ever mention how the server handled the situation?  Probably not; the server is usually only mentioned as an extra in the bad scene.  That is because servers sometimes act as if everything that goes wrong is the kitchen's fault.  If we really think about it, they are the last pair of eyes to see the food before it reaches the table; they should have the final say in its appearance. 
At the risk of seeming pessimistic, I want to caution you if you don't have many guests filling out those cards.  It isn't because everything is always great.  Most of us feel that our comments won't be taken seriously and nothing will change as a result of our taking the time to fill those cards out.  We have become accustomed to mediocre service at the hands of a young, inexperienced person who thinks that serving food is a better way to make money than selling clothes in a trendy store at the mall.  We have become accustomed to asking for another drink because our server is busy chatting with his/her friends and wants guests to move quicker and leave more money.  We have become accustomed to our servers not having any suggestions about some of the highlights of the menu, in fact, not knowing much about the menu at all!  All of these things we have become accustomed to and therefore we don't even think about asking for a change.  Most of us don't know it could be so much better!

Guess what?  Your servers don't know it could be so much better, either.  They are getting the kinds of tips they deserve for their lack of attention to guests and the details that go along with them.  Your guests are giving what they think the service is worth.  When they walk out your door they might tell you that the food was great, or maybe the food was a little less tasty than usual, but they will never tell you that the service was only ok or even bad.  Understand that we live in a society where it isn't ok to be confrontational and tell someone that they aren't performing well.  In our politically correct society, if you tell Bob or Jane that you don't like the way he/she is serving you, you are being rude and demanding.

What guests will do is tell you about the food because they never have to meet your kitchen staff.  They know they may have to deal with the same server again.  We don't feel like our comments are going to be heard and treated as a comment.  We feel like we're going to be labeled a nasty customer and treated worse.  Most customers are forgiving and will give you another chance and return.  If, however, they receive the same lack of care in service, they will quietly go away.

Who do your guests tell about their bad experiences?  They tell their friends, family and neighbors.  Sometimes they tell your competition.  And when they find out what I do, they tell me at great length and they insist that I go to you and train your wait staff.  They want to continue dining in your restaurant.  They want it to be more pleasurable than it currently is.  What you see is that your staff is taking orders and getting the food out in a timely manner.  Your guests see that, too.  They want more from a dining experience and they are willing to give more tip money when they get it.

When a server suggests wine or particular dishes and sides to go along with them, your guests don't perceive them as being pushy.  On the contrary, when done in a professional manner and with some charm and class, they perceive it as great customer service!

Guests may not be able to articulate these ideas to you.  They just know that something is missing.  Ask any businessperson who frequently dines with potential clients and he/she will tell you he/she knows the best places to take someone for smooth, seamless service.  Your staff deserves to know that they could be earning more money.  You could be earning more money because they earn more money.

You can bring these issues up at your next employee meeting, but most servers never think you are talking about him/her.  Another shameless plug for my business!  Allow me to come in and interact with them in some role-playing situations.  They don't need to be accused of being guilty of bad customer service; they will figure it out for themselves through the course of my class.