A tech-stack signal: 500 Shopify stores checked for $0.48, and the 36 on Klaviyo with no review app

Which online stores use Klaviyo but no review app, Mailchimp but not Klaviyo, or no email tool at all, read from their own homepages and DNS at $1 per 1,000 domains. The free store list, the exact Actor input, a real run with its cost, the segments, and an n8n workflow that fills a Google Sheet.