Characters
Well, not much goes on in a one-Starbuck's town like Sunnydale.
— Xander
Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker dismisses the town as dull, measuring its lack of excitement by the number of coffee-chain shops it has: one. The joke turns a brand name into a yardstick of small-town sleepiness, delivered with a hedging 'Well' and a dry, self-aware shrug.
Context reviewed