Power
When it comes to combining style and comfort, you're the go-to expert, intrepid upholsterer. You'll wield plenty of influence in the form of advice for your customers. When some dot-com entrepreneur strikes it rich and wants mink covers for his Ski Nautique boat cushions, you can point out the advantages of standard vinyl.
Or, because you might figure he can afford to cover them twice, you could let the man have mink boat cushions.
You'll also find plenty of normal people who've found a slightly worn out, yet nice piece or set of furniture that doesn't match their home décor. They'll come to you for your vast knowledge of materials and keen style sense as much as your ability to slap a new cover on it.
Then there are situations where the tail wags the dog, meaning the furniture sets the tone for the whole room. Say you re-cover a '50s-era soda shop booth for a client with an authentic red and black checkered pattern. Well, now the kitchen doesn't match, and you get to play the part of interior decorator.
For starters, you recommend she retile her kitchen and give the walls a matching coat of paint. At this point there's no stopping you, and you convince your client to knock down a wall, install more booths, set up a soda fountain, and wear an apron and paper hat all day. You know, just for kicks.
Okay, we got a little carried away on that last one. In reality you won't have much power over anything not related to furniture.