I need to hit at least 1500-2000 messages sent on each sample size before I can confirm this with certainty, but so far a 1.06% difference.
No personalized line (872 messages) - 2.18% response rate
Personalized line (1019 messages) - 3.24% response rate
Monthly Impact: 36,000 messages, that's 360 additional responses, 4 booked calls, and 15k in revenue.
To make personalized lines you can filter by defining categories of each person and have ChatGPT write up things that are specific to those categories (I would still do some tweaking as ChatGPT is easily detected by now).
EX: Filter by university attended
Filter: University of Central Florida
Subject: Go Knights!
Personalized Line: Hey John, Go Knights! What's your favorite memory from UCF?
Using this method allows you to gather a couple hundred to thousand leads and repurpose the same personalized line for all of them.