You've seen it a hundred times: a creator posts something great, and the caption says “comment GUIDE and I'll send you the link.” Minutes later, hundreds of people have commented — and every one of them gets a DM with the link.
That single move does three things at once. It spikes the comment count (which the algorithm loves), it starts a direct conversation with every interested person, and it gets your link into their hands without the dreaded “link in bio” detour. This guide breaks down exactly how to run it well.
Pick a keyword that converts
The best keywords share three traits: they're short, easy to spell, and impossible to misread. One word, all caps, five letters or fewer. GUIDE, DROP, LINK, SHOP, YES. When someone has to think about how to spell your keyword, you lose them.
Tie the word to the thing they're getting. If you're sending a free guide, “GUIDE” is perfect — it tells them what they'll receive and doubles as the trigger. Avoid clever phrases or anything with spaces; “send it to me” is four chances to typo, and typos mean missed DMs.
Rule of thumb: if you can't say the keyword out loud once and have a stranger spell it correctly, it's too complicated. Pick something simpler.
Write the caption that gets comments
A comment-to-DM caption has three parts, in this order: the hook, the value, and the ask.The hook stops the scroll. The value tells them what's in it for them. The ask tells them exactly what to do.
Here's the formula in action: “I spent 3 years learning this the hard way so you don't have to. I put it all in a free guide — comment GUIDE and I'll send it straight to your DMs.” Hook (3 years the hard way), value (free guide), ask (comment GUIDE).
Make the ask the very last line, and make it a single clear instruction. Don't bury it in a paragraph, and don't ask for two things. One keyword, one action. The easier you make it, the more people do it.
Reply to a few of the early comments yourself, too. It signals to the algorithm that the post is sparking conversation, and it nudges more people to join in.
Craft a DM they actually click
Getting the comment is half the job. The DM is where the click happens — and most people waste it with a cold, linky message. Your DM should feel like it came from a person, not a robot.
Open warm, deliver fast, and put the link on its own line. Something like: “Hey! So glad you asked 😊 Here's the guide I promised 👉 [link]”. The greeting makes it feel personal, “as promised” reminds them they opted in, and the arrow points straight at the thing to tap.
Keep it to one link. Every extra link splits attention and lowers the odds they click the one that matters. And send it instantly — interest is highest in the first few seconds after they comment. A DM that arrives an hour later lands cold.
This is the part DropThis handles for you: the moment someone comments your keyword, the DM fires automatically, in under a second — with the exact message and link you set. No sitting by your phone.
Read the numbers
Two metrics tell you almost everything: comment rate (how many people commented your keyword relative to reach) and DM-to-click rate (how many who got the DM actually tapped the link). The first tells you if your caption worked. The second tells you if your DM and offer landed.
If comments are high but clicks are low, your caption is great but your DM or offer needs work. If comments are low, the caption or the hook is the problem — the DM never even got a chance. Read them together and you'll always know what to fix next.
Track it per post and per keyword so you can spot patterns: which offers pull, which captions convert, which posting times work. Over a few weeks you'll have your own playbook — the exact formula that works for your audience.
DropThis tracks every DM sent and every click, grouped by keyword, so you don't have to count comments by hand or guess what's working.
That's the whole playbook
Pick a clean keyword. Write a caption that hooks, gives value, and makes one clear ask. Send a warm DM with one link, instantly. Then read the numbers and adjust. Do that consistently and your comments stop scrolling away and start turning into traffic.