Sincerely: Personalized direct mail at scale, for B2B teams.

Hi Product Hunt, I’m Adam, and I'm building Sincerely. Outbound email became nearly free, and inboxes filled with sequences nobody asked for. Physical mail went the other way. There’s less of it, so a good letter gets read. But running a careful B2B mail campaign still meant spreadsheets, a designer, a printer, and tracking links that couldn’t tell you whether any of it worked. Sincerely puts that chain in one place. Bring a list from Salesforce, HubSpot, or a CSV, or describe who you sell to and the agent finds the accounts. It checks every address, researches each company, and writes a piece for one person from sourced facts you can review. A person approves everything before it prints. The part I care about most is measurement. Most mail and gifting tools report “influenced pipeline”, which only tells you that a deal touched the campaign. Sincerely holds out a random set of accounts and reports lift with a confidence interval. When the data isn’t there yet, it says “not proven yet”. You can set everything up for free, and nothing mails until you pick a plan. A $199 pilot covers a first real send. It works in the US and Canada today. I’d love feedback, especially from anyone who has tried to measure direct mail before.