Yes, even when they aren't. If you think about it, they ARE why companies are in business. Every business has customers no matter how large, small, or what type of business. Without them we could just drop out of college and sit on the couch and ponder the things we could be doing. Without them we would have "No phones, no lights, no motor cars, not a single luxury" and we might as well be stranded on a deserted island. Customers give us reason.
Traditionally large companies had all the money, power, and employees, and could service customers faster and more efficiently. In today's world the playing field has leveled thanks to technology as smaller companies can use services on demand and have the same footprint as the large companies. For instance, when I wanted cookies when I was younger I had to either drive to the store and buy them from the bakery or the shelf, or bake them. With the internet and the technology wrapped around it today you can order them online and then they deliver them right to your door. You can see this trend in many markets. Need a used car? No need to go get harassed by a used car salesperson anymore, just go to eBay Motors and if the car doesn't work out you can always sell it on Auto Trader. That is much better than a classified ad in a newspaper that fewer and fewer people read. Technology is a wonderful thing! It also makes it easier for the customer voice to be heard.
In the past if you didn't like the service you received at a restaurant you could complain to the manager and maybe get a free dessert or appetizer on your next visit. If a mechanic overcharged you for work on your car you really didn't have a leg to stand on you simply paid and grumbled. If someone broke their word and took money for a service, then didn't actually complete the service, you could sue them but in many cases the rule "you can't squeeze blood from a turnip" applied and you were still out of your hard earned money nonetheless. Sure, you could use the word of mouth rule, "they tell two people and so on and so on" but in most cases this was a futile attempt at restitution. Technology is changing that. Today it is corporate and personal blogs, wiki's, social networking sites, and forums that help keep individuals and companies in line with customer expectations. A derogatory blog about your company can really affect your business depending on its viral popularity. Forum posts can get out of hand and prompt unhappy customers from many years past to jump on the band wagon again and tell of your shortcomings. This makes reputation management something that all companies have to consider. Times have changed for the marketplace and the best reputation management is to simply make every customer a happy customer.
I think in reality all customers aren't always right (I will await the beating in the comments!) but as a Service Company it is our job to always say "yes" when asked for something by a customer as long as it is legal and Internet-friendly. The request is usually something we should be doing anyway. In the long run you have to try to create a long-term relationship with every customer and if you can then it becomes a "win-win" for everyone.
Now, go tell two friends!
I wonder if WiFi is available on my deserted island yet.