Tickling is considered a fetish but I'm not sure why. It's almost considered a highly kinky kink but if you ask me, I think it's therapeutic and pure clean fun.
Now that's not to say you can't combine other elements into tickling that raise the bar of enjoyment. One of my favorite sessions was with a boyfriend and girlfriend team. I tickled both of them at the same time and then the girls tickling the boy and then the boyfriend and I tickling his girlfriend.
I gave him some good tips to make her scream in delight. It was such amazing goodness!!!