I usually pop in when it's quiet to have my dd measured at the start of the hols then order the style we want online from Very or Next.
This, and other similar posts, is breathtakingly wrong and selfish.
Clarks is not a public service; it is a business. If you intend to buy from its competitors, don't use the labor from another store to subsidize the lower cost of your shoes elsewhere. That labor cost is baked into the higher price of a Clarks shoe.
It's a huge problem with bookstores across the country: people come in, browse, read the staff recommendations, and then go buy the book on Amazon. It's one of the reason brick and mortar bookstores close: they're subsidizing Amazon with their labor.
If you absolutely need a cheaper shoe, I understand entirely. Next has a very good measure-at-home guide and you can buy and return.
I agree that Clarks' sales technique is outrageous.
I also think that posters who go into Clarks to get measured and then go online to buy their shoes from another, cheaper competitor are killing the high street.