I think it's fine to give your kitty treats, if they are at a healthy weight, etc.
I've been giving our new kitty Sofie extra treats every day (just little treat cat cookies, etc). She was severely underweight when we found her though, and needs to gain a little weight.
Our other kitty Ebony is overweight so she is on a fairly strict diet (she doesn't care very much for treats anyway). Our vet told us that if we do give her a treat, we need to reduce the amount of regular food she is getting on that particular day.
I found some Webbox treats which are quite healthy and sort of like jerky. The cats love them, and it's not like giving them candy. So I use them whenever I am trying to intice them towards better behaviour
We give our cats treats everyday. It's a form of exercise for them. We always throw them across the floor so they have to chase them down and catch them. And we buy the MediCal treats that are only one calorie, so they probably burn that off just by chasing it anyway.
mine were getting treats every day for the last 7 days, but that was because nabu was getting medication. normally i give treats a few times a week. i usually have several kinds open to choose from too.
Tailer and Forest get treats a couple times every day. They also like to chase theirs. In fact, if I don't throw it far enough for Forest (who has CH), he gives me a disgusted "don't patronize me" look.