How to Run a Flash Sale With a Comment Keyword

A flash sale on Instagram works when the gap between "I want it" and "I paid" is a few seconds long. The simplest way to close that gap is a comment keyword: you announce the deal in a reel, ask people to comment SALE, and an Auto-DM sends the checkout link instantly. With the Viralyze app you also set an end time, so the automation pauses itself when the offer closes.

This guide walks through the setup, the timing, and the mistakes that quietly cost sales.

Why use a comment keyword instead of "link in bio"?

Because a comment is one tap and a bio visit is four. During a sale, every extra step loses buyers who were only half convinced.

A keyword also does two things a bio link cannot. The comments pile up publicly, which signals demand to everyone else watching. And each commenter becomes a contact you can reach again inside Instagram's 24-hour reply window.

How do I set up the flash sale automation?

Setup takes about a minute once your product page exists. Here is the order that works:

1. Create the discounted product in your shop. In Viralyze, digital downloads, courses and 1:1 sessions each get their own checkout page with UPI, cards and net banking. 2. Post the reel or carousel announcing the sale with a clear instruction: "Comment SALE for the 40% link." 3. Create an Auto-DM automation on that specific post. Add keywords SALE, Sale, "sale link" and a 🔥 emoji; matching is not case-sensitive and copes with typos. 4. Write the DM: the price, what it includes, the deadline, and the checkout link. 5. Set auto-pause to the exact date and time the sale ends. 6. Run the live tester with a sample comment, then turn it on.

The public reply ("Sent you a DM 💌") is rotated between variations, so the thread does not look like a bot shouting the same line.

What should the DM say?

Keep it to four lines and put the deadline early. A working example for a 24-hour sale on a ₹499 Notion planner:

"Hey! Here is the flash sale link for the Content Planner. ₹499 → ₹299 until 9 PM tomorrow. Pay by UPI or card, download instantly. [link]"

Because Viralyze applies AI variations, each buyer sees a slightly different wording of this message, which keeps it from reading as a mass blast while the offer stays identical.

How do I keep the sale from running past its end?

Use auto-pause rather than remembering to switch it off at midnight. You can pause after a number of DMs (useful for "first 50 buyers" offers), after N days, or on a date.

When the automation pauses, the status changes to Paused on your dashboard. If someone comments after that, nothing is sent, which is better than DMing a link to a page where the price has gone back up. If you want to extend the sale, edit the pause date and the automation goes Live again.

What should I check after the sale?

Open the per-automation funnel: comments, matched, delivered, clicked, signed up. If comments are high but clicks are low, your DM copy or price is the problem. If clicks are high but purchases are low, the checkout page needs a clearer description or a trust line such as "instant download, refund within 7 days".

Export the contacts list to CSV. Everyone who commented but did not buy is a warm audience for the next offer, and the source tag tells you which reel they came from.

Frequently asked questions

**Can I run the same keyword on more than one post?** Yes. You can set a trigger for a specific post or for comments on any post, so a sale announced across three reels can share one automation.

**What if the same person comments twice?** Instagram allows one private reply per comment within seven days, and Viralyze follows that rule, so a second comment can receive a second DM without breaking Meta's policy.

**Do I need a Facebook Page to run this?** No. You need an Instagram Business or Creator account and you log in on Meta's own screen; no Page or flow builder is required.

Start the 7-day free trial of Viralyze, no card needed, and have your first flash sale keyword live before your next post.