Something for good measure

• A small gift (especially one given by a merchant to a customer who makes a purchase)
• City ace in Epping sent up small gift
• Tip in gale at sea requires loading of program

Wikipedia Word definitions in Wikipedia
A lagniappe a small gift given to a customer by a merchant at the time of a purchase. Langniappe may also refer to: Lagniappe (newspaper) , an alternative newspaper in Mobile, Alabama Lagniappe (album) , a Hurricane Katrina benefit album by Saddle Creek ...

Wiktionary Word definitions in Wiktionary
n. (context Louisiana Mississippi Trinidad and Tobago uncommon English) An extra or unexpected gift or benefit, such as that given to a customer when they purchase something else.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Lagniappe \La*gniappe\, Lagnappe \La*gnappe"\, n. [Also spelled lagnappe . Etym. uncertain.] In Louisiana, a trifling present given to customers by tradesmen; a gratuity. Lagniappe . . .is something thrown in, gratis, for good measure. --Mark Twain. A tip ...