A large list with low engagement is fragile. Mailbox providers watch whether people open and interact with your emails, and messages that are ignored increasingly land in promotions tabs or spam. Advertisers pay for attention, not list size. Paid conversions come from readers who already feel involved.
Improving engagement is less about tricks than about relevance and conversation. Send people what they asked for, ask what they think, act on the answer, and test small changes rather than guessing.
Inkwave provides the pieces for that loop: interactive polls and surveys inside issues, segmentation to target content, A/B testing to learn what works, and automation to re-engage readers who drift away.