How do you send coins to a friend on FarmVille?

You can not directly send Farm Cash to your friends. The ways of obtaining Farm Cash are as follows:

• You may purchase Farm Cash with real money, via a PayPal account or a credit card.
• Inside a Mystery Gift (sent to you by a friend) there may be 1 Farm Cash inside, although this is unlikely.
• Every time a player moves up 1 level, they will receive 1 Farm Cash.
• 1 Farm Cash may be found inside a Golden, Cornish or Scots Grey Mystery Egg.
• If you install the Zynga Toolbar, you receive 10 Farm Cash.