“It’s nice to be important, but it’s more important to be nice” has been a business saying since at least 1950, when it was cited in June 1950 from a Georgia newspaper and in November 1950 about a successful Georgia business man. The saying now appears on many Internet lists of one-liners.
 
   
12 June 1950, The Robesonian (Lumberton, NC), pg. 4, col. 2:
Other Papers Say:
IT’S NICE TO BE IMPORTANT—BUT
(Pelham, Ga. Journal)
(...)
He’s an important executive in a big business, but he had discovered that it was also important to be nice. That is why he was important!
 
Yes, it’s nice to be important but it’s far more important to be nice. The important man who doesn’t know that will not remain important very long.
 
23 November 1950, Laurens (IA) Sun, “Neil’s Nibbles,” pg. 2, cols. 2-3:
“Many people forget that while it is awfully nice to be important, it is much more important to be nice!” The editor of the Bremer County Independent saw this legend on a card in the office of a successful business man in Georgia. It’s worth remembering!
 
2 July 1953, Albuquerque (NM) Journal, pg. 18, col. 5 ad:
GUS SAYS
Most of us establish and build our business on the respect and good treatment of our customers. We call this good will. Good will is a tangible asset of any business and as a tangible asset, a growing will increases the value of most business. It doesn’t take long for the man with a push to pass up the man with a pull. It is very nice to be important…but it’s more important to be nice. Attend the greatest sale of the year now going on at your friendly store in the Heights.
Gus Patterson’s
THE SHOP FOR MEN
 
19 July 1953, Aberdeen (SD) American-News, “Of New York” by Walter Winchell, pg. 4, col. 4:
Talk about copycatting, Tony Curtis and Bob Olin were credited this week with: “It is nice to be important but it is more important to be nice.”
 
25 January 1954, Springfield (MA) Union, “Looking Over Hollywood” by Hedda Hopper, pg. 9, col. 6:
Sidney Blackmer, noticing some actors’ snubbing fans, writes: “It’s nice to be important, but it’s more important to be nice.”
 
Google News Archive
30 October 1954, New London (CT) Evening Day, pg. 3, col. 7 ad:
IT IS NICE TO BE IMPORTANT,
BUT IT IS MORE IMPORTANT TO BE NICE. Franklin
(The Winthrop Trust Co.—ed.)
 
Google News Archive
1 February 1961, Milwaukee (WI) Sentinel, “Dear Abby” by Abigail Van Buren, pt. 1, pg. 13, col. 2:
CONFIDENTIAL TO “TROUBLED TEEN”: It’s nice to be important, but it’s more important to be nice.