Sir, Professor Byron Sharp's assertion that marketers using promotions to build brand loyalty are like medieval doctors whose bloodletting tactics inadvertently kill the patient is wide of the mark ('Promotions don't build loyalty, they leech life out of brands', The Grocer, 22 January).

Creating loyalty is the holy grail for any brand. If you have a loyal customer base, what you actually have are brand ambassadors who will act as wholehearted advocates for your product. Given the influence of social media in spreading and creating word-of-mouth opinions about brands, brand loyalty is more important than ever. Another fundamental problem is that it typically costs brands three to five times more investment to acquire new customers than it does to retain their existing ones.

The picture Sharp paints is one of promiscuity with promotions consumers aren't loyal, they flip from brand to brand depending on where the best offers are. He is right to an extent, and this is an issue brands face. But I would argue he's got it the wrong way round it is the very tactics of promoting promiscuity rather than brand loyalty that are 'killing the patient'.

Instead of medieval doctors, Sharp is talking about medieval promotional tactics that are still around today, as opposed to some of the more intelligent solutions based on the needs of smart, savvy shoppers who want to be seen to make the right brand choice. That's how you build brand loyalty.

Neil Jenkinson, marketing director, Dialogue141