$9 billion Stripe just bought a payments startup backed by Eric Schmidt as it goes after even larger customers

Stripe, the $9 billion payments processing startup, has purchased Index - an in-store payments startup backed by former Google CEO Eric Schmidt's venture capital firm Innovation Endeavors. Index provides software for in-store payments systems, like the PIN pads that you probably already use to pay with a debit or credit card at your local Target or pharmacy. Its biggest claim-to-fame…