The most common and most likely answer to this crossword clue is the 7 letter word STOCKED
I've seen this crossword clue in The Daily Telegraph
S
T
O
C
K
E
D
Buddy explains!
The straight part
We know that "What customers want a shop to be" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what customers want a shop to be = stocked.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does STOCKED mean?
STOCKED verb- To have on hand for sale.
- To provide with material requisites; to store; to fill; to supply.
- To allow (cows) to retain milk for twenty-four hours or more prior to sale.
- To put in the stocks as punishment.
- To fit (an anchor) with a stock, or to fasten the stock firmly in place.
- To arrange cards in a certain manner for cheating purposes; to stack the deck.
- Having been replenished with stock.