EE has been fined £100,000 for sending over 2.5 million direct marketing messages to customers without their consent. Marketing messages were included in customer service messages with administrative content. While the ICO accepted that EE had not deliberately set out to breach PECR it should have been aware that even simple messages promoting other goods and services constitutes marketing.
Normally the soft opt-in would apply when sending marketing messages to existing customers. That provides a basis for promoting the same or largely similar goods or services to people who have bought from you in the past, provided the right to object to direct marketing is made clear in every communication (the unsubscribe option) and is respected when exercised.
In the case with EE, an individual who had opted-out of receiving marketing materials (thereby objecting to the use of his data for marketing purposes) received one of the service messages with an embedded marketing statement.
Marketers need to be clear as to what is a marketing message and what is a customer service message and compliance personnel need to check that the lines are not being crossed. Consider also the practice of using a promotional message in email footers. You might not even notice the message is there because it is part of the “wallpaper” of your email but if you are corresponding with customers using your email, it can be interpreted as marketing as the case with EE shows.