Some gifts are Free to send (limit of 10 per day), some cost $s, and some cost €. Different gifts go on either your Land regions, or on your Beach.
With Build 86 update, the bought-gifts now do not decrease the free-gift counter, and you can only send 1 free gift per friend but as many bought gifts per friend including multiples of the same item - however the bug is now that you can now only send a maximum of 10 gifts total per day. eg: You could send 1 x Hammock and 9 x Crabs to 1 friend (or 1 gift free or bought to each of 10 friends) but then you can not send any more gifts to any friend for another 24 hours, even if the counter says you can still send 9 or 10 free gifts...
All Gifts placed act as Decorations - i.e. they do not require road, staff or energy, do not earn income or break, can not be upgraded or moved to warehouse, the same as Monuments except they do not count towards the Monument Awards.
The person giving the gift pays for the gift and receives XP. The person receiving the gift can earn XP only by bulldozing the gift, but will earn the luxury score points for placing paid gifts.
As of Version 2.0.8, the above awards have been added related to giving gifts. Also, several recent Special Events have included unique gifts and Special Awards for giving and/or receiving these gifts.