a16z: bot 403 blocks double as Amazon cracks down on agentic commerce

a16z Newsletter · rss · 2026-10-16

This Week in Charts (a16z)

Agents denied

Cloudflare data shows the share of 403 "Forbidden" responses served to agents and bots has roughly doubled since summer, as big etailers like Amazon block agent shoppers to protect customer relationships and ad revenue.
Retailers also fear fraud and returns: NRF data shows return rates have doubled and return costs tripled since 2019, with dispute abuse the top fraud concern—problems agents could amplify.
Consumers aren't ready either: only 25% would let AI buy consumer goods (minus luxury), while 42% don't trust AI purchases at all. Similarweb clickstream shows AI sits mostly in the "middle phase" of shopping journeys (research/price checks), rarely at discovery or checkout.

Super-Pareto TikTok Shop

Marketplace Pulse: 8.4% of sellers post 1,000+ videos and capture 60% of sales; the top 1% of sellers drive 60% of sales, the top 10% drive 93%.

Chip price spillover

BLS data: prices paid for semiconductors by computer makers are up over 25% YoY due to AI capex. Hyperscalers keep buying, but PC shipments (IDC) have dropped substantially this year as everyone else postpones upgrades—the cure to high prices is high prices.

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