Hashtag promos: the Facebook comment reply template
Run one rule across a whole campaign by tagging the posts instead of listing them. There is one fact that catches almost everybody, and it is worth reading before you build this: the hashtag is read from the post, not from the comment.
Power-user. Someone running a recurring promo who does not want to paste post IDs into a rule every time they post.
Checked against the product on
When this fires
Paste these into the rule’s keyword list. Any one of them matching is enough — keywords are an OR list, not an AND list.
promodiscounthow muchavailcodesale priceราคาโปร
How Mentbot reads them
- Matching is a plain substring test, not a whole-word test. A keyword matches anywhere inside the comment — which is why the list below matters.
- Case is ignored, and text is NFKC-folded first, so ＳＡＬＥ matches sale and full-width or styled characters still match.
- Thai, emoji and any other script work the same way: the comment is compared as text, with no language detection.
- Leading and trailing spaces in a keyword are trimmed, and a blank keyword row never matches anything.
The public reply
Add these as separate reply variants on the rule. Mentbot picks one at random each time a comment matches, so the same post does not fill up with one identical sentence.
- Variant 1
Promo price is live on this post 🔥 Sent the details and the code to your Messenger.
- Variant 2
You're on a promo post — the discount applies 🎉 Check your inbox for the code.
- Variant 3
Yes, this one's in the sale 🏷 Price and code are in your Messenger now.
{comment} is replaced with the commenter’s own text. It is the only token Mentbot substitutes — there is no {name} or {page}.
The Messenger DM
The private reply Mentbot sends to the same commenter. On Facebook this is a Messenger private reply to the comment, so it only works while Facebook’s reply window for that comment is open.
Hi! You asked about "{comment}" on one of our promo posts. Promo price applies to everything on this post while the campaign runs. Reply here with what you want and we'll apply it. Ends Sunday.
Settings to turn on
The four switches on the rule, and what this scenario needs from each.
| Setting | This template | What it does |
|---|---|---|
| Reply once | On On. One promo explanation per person per post. | Answers each commenter once per post for this rule — and an attempt Facebook refused still counts as that once. The same person commenting again on the same post gets nothing more from this rule, but a different rule can still answer them, and the same rule answers them again on a different post. |
| Mention the commenter | Off | Puts an @mention of the commenter at the front of the public reply. It applies to the public reply only, never to the Messenger message. |
| Hide the comment | Off | Hides the comment once this rule has answered it. The author and their friends still see it; everyone else does not. Separate from your Page’s moderation filters, which run earlier. |
| Like the comment | On On. Cheap engagement on the posts you most want engagement on. | Likes the comment from the Page, straight after the public reply goes out. |
Scope
Where the rule is allowed to fire.
The rule only runs on posts whose own text contains the hashtag. The hashtag is read from the post, never from the comment.
One hashtag per rule — the field holds a single hashtag, not a list. Put it in your post's caption when you publish, and the rule covers that post automatically with no rule edit. Leading # characters are stripped when the rule is saved, so "#SALE" and "SALE" are stored the same.
When two rules could both answer
Exactly one rule answers a comment. Mentbot ranks every rule that qualifies and runs the most specific one; the rest are recorded as outranked, not run.
- A rule limited to a list of posts wins first — even if it also has keywords.
- Then a rule with a hashtag or keywords.
- Then the catch-all with neither.
- If two rules tie on that rank, the older one wins. There is no priority field to set.
What will not match
Comments a seller expects this rule to catch, and does not. Each one follows from the matching rules above.
| The comment | Why it does not fire |
|---|---|
| A comment containing #SALE on a post that does not have #SALE | This is the one. The hashtag is read from the post's own text — the Facebook post message, or the Instagram caption — and never from the comment. A commenter typing your hashtag does not make the rule fire, and no amount of re-reading the rule settings explains why. |
| #SALE2026 on the post when the rule's hashtag is SALE | Hashtag matching is an exact match against the tags extracted from the post, not a substring test — the opposite of how keywords work. "sale" does not match the tag "sale2026". This inconsistency is real and worth memorising: keywords are substrings, hashtags are exact. |
| A post you have just edited to add the hashtag | The post's tags are cached for about five minutes after they are first read. Add the hashtag and comments arriving in the next few minutes can still be skipped as a mismatch. Wait, or add the hashtag when you publish rather than afterwards. |
| Comments on a post covered by a post-scoped rule | A rule with a post list ranks above a hashtag rule and wins. If you scoped something to that post — a live, a giveaway — it answers instead. |
| Sticker-only and emoji-only comments | A sticker carries no text, so a rule with keywords never matches it. An emoji-only comment is ordinary text, but none of the keywords above is an emoji. |
What Mentbot will not do here
Stated plainly, so you do not build a workflow on top of something that is not there.
- One hashtag per rule. Two hashtags means two rules, and they will tie on specificity with each other.
- The hashtag is matched case-insensitively and NFKC-folded, like keywords — but as a whole tag, unlike keywords. #SALE does not match a post tagged #SALE2026.
- Checking the hashtag requires reading the post's text, so it costs an extra call per post, cached for five minutes. Post-scoped rules are checked first precisely so a post-scoped rule that misses does not pay for it.
Cost at your comment volume
Rules are not metered separately — you pay for comments handled per day across all your Pages, and every plan includes every feature. Prices come straight from the pricing page.
| Comments per day | Plan | Monthly |
|---|---|---|
| 100 | Basic | $9 |
| 1,000 | Pro | $19 |
| 3,000 | Premium | $29 |
Unlimited Pages on every plan, and a 14-day free trial.
Questions
Why is my hashtag rule skipping every comment?
Almost certainly because the hashtag is not in the post's own caption. Mentbot reads hashtags from the post text, not from comments — a rule tagged SALE only runs on posts whose caption contains #SALE. A skipped comment records why it was skipped, so you can check rather than guess — though with several rules it shows the first reason from your oldest rule, and keywords are checked before the hashtag.
Can the commenter trigger a rule by typing a hashtag?
No. If you want a word in the comment to trigger a rule, that is a keyword, not a hashtag — and keywords match as substrings, so "#sale" in a comment would be caught by a keyword of "sale".
Does the hashtag have to include the # symbol in the rule?
It does not matter. Leading # characters are stripped when the rule is saved, so both forms are stored identically.
Hashtag rule or post list — which should I use?
A post list if the campaign is a handful of known posts, because post-scoped rules also outrank everything else. A hashtag if you post frequently and do not want to edit the rule each time. You can run both: the post-scoped one wins where they overlap.
I added the hashtag to a live post and nothing changed.
Give it five minutes. The post's tags are cached briefly after they are first read, so a caption edit is not picked up instantly.
Other templates
Related guide
The long-form version of this, and the tool comparisons.
Every behaviour on this page is checked against Mentbot’s own source. If the product changes and this page does not, tell us.