Just my opinion, but there are three aspects to a gig: Did the audience like you Did you get asked back Did you sound good Professionals care about all three. I don't consider a gig successful unless I can say yes to all the above. I've had plenty of gigs where the band sounded "OK" but the audience liked us and we got asked back. I've had a handful when the band was on fire, the audience liked us and we DIDN'T get asked back; also not a success in my book. I would also recommend recording the band. I can't tell you how many gigs I've played where I though the band was "meh" and I listened to the recordings and found out we actually sounded pretty good.