Dear utility company,
Because you're such a valued utility supplier, we your customers would like to make you a special, limited time offer. For only minus the cost of a letter and/or phone call to each of your customers up to several times a year, we can offer you a fully not-annoyed by unrequested interruptions customer base, representing a possible saving of hundreds of thousands of pounds per year, depending on how much junk mail you send out and how many unsolicited phone calls you make.
What's more, you'll receive absolutely no snippy responses from ordinary people who were busy doing real things with their lives before you interrupted them to try to offer them a slightly different package than what they're already receiving. On top of that, you can sleep soundly knowing that 99% of your junk mail isn't going straight to a landfill, reducing harmful effects on the environment.
Plus, if you act today, you could also reduce the amount of people you annoy who aren't your customers yet, by not cold-calling any of the phone numbers you've acquired through slightly suspect means in order to try to expand your customer base. With these savings, you could put more money into making your services more reliable, or even slightly cheaper, further increasing the happiness of your customers.
Why not act today? We're not waiting for your call.
The portion of your customers who are happy with their services right now but also quite capable of finding a better deal if the need arises