It assumes your customers
a) don't mind being interupted at which is essentially a self service station (if they wanted to be served, they'd go to starbucks?). At times I prefer minimum contact when purchasing something. Being asked, "do you need any help" is perhaps the most annoying question ever concieved. If I wanted help, I'd say, "excuse me, could I have some assistance". But then I wouldn't find an assistant if I actually wanted one now, would I :lol:
b) do not know how to make coffee
The video suggests people are unaware that the syrups are free. However, Gary didn't address this. Indeed, I'd think he was trying to load me up with syrups to up his commisssion. Ok, I know he's not on commission, but why not put up a sign next to the syrups saying:
"FREE"
That might help
Gary also looked a bit scary. He kind of pounced on the customer. He may not return for fear of Gary pouring him a strawbery latte. (He doesn't like strawbury and hates lattes). But Gary didn't ask him that now, did he? Perhaps it would have been better for him to say:
"may I make a suggestion? Perhaps you'd like to combine x, with y and top up with z. Be adventurous, after all, any y or z is complimentary. I'll tell you what, I'll make my special, and you see if you like it".
Or you could get a sign to replace Gary.