Serta Simmons Bedding, an Atlanta-based portfolio company of Advent International, agreed to acquire Phoenix-based mattress and bedding company Tuft & Needle.

Why it matters: Because direct-to-consumer mattress startups like Tuft & Needle are estimated to have taken around a 20% market share from incumbents, which means this deal may be just the first of many. Plus, Tuft & Needle is the rate company in this space to have not taken any venture capital.

• Reminder: Mattress upstarts like Tuft & Needle, Casper and Leesa use technology to sell product, but they are not technology companies.
• Bottom line: "Selling out to Big Mattress, as some observers refer to old-line players like Serta Simmons, might seem counterintuitive... But the landscape is changing rapidly as direct-to-consumer mattress brands sign deals with retail stores and old brands try to gain online shoppers." — Amy Feldman, Forbes