Marks & Spencer ranks #20 of 20 UK retail sites with a B- (80%) quality score vs the 85% category average. 219 issues detected vs 130.2 avg. Biggest competitive gap: Security issues (24 vs 10.3 avg, +14 above peers). Competitive strengths: fewer issues than avg in UX.

Below the median — but that means clear opportunity to differentiate. Biggest ROI: fix the 24 Security issues (peers average 10.3). Start with: "JWT Token Exposed in Network Request URL".