When I was pretty new, I had a noobish Icon with a Chikorita with a Crown on it. I had this thing for half a year after =Yakalentos made a free "Lick Icon" for me when they were spreading around the Community.
The Icons I have nowadays though, I use for like, uuhhh... a week maybe?
I had one of Drifloon that I got from deviantart search because the maker said you could use it for free for like...two and a half years.
Mainly because When I first moved to this account I had the same icon for like a year that I got tired of and then I just slapped that Drifloon on there for the longest while cause I was focusing on FA for the longest time. LOL