Write promo copy
CreativeWriting
Set the channel, the length and the phrasing to avoid, and get three versions of the copy.
Fill the blanks and it copies as you filled it
Write me some promo copy. - What I'm announcing: - Where it goes and how long: - Who sees it: - What to avoid: - Three versions
0 of 4 blanks filled · anything left blank copies with its brackets
What this prompt does
Compared with asking the same thing without the length and format lines.estimate
Estimated output tokens
1,400
Asked loosely
700
This prompt
Energy (Wh)
1.215
Asked loosely
1.215
This prompt
Token counts are estimated from character counts, not measured. Energy uses the per-band figures measured by Jegham et al. 2025 as published.
A shorter answer, but the same energy band. The measurements are per band, and this much does not cross one.
Reported backfire — Specifying output lengthSpecifying a length longer than needed backfires (a 34% increase in 11% of scenarios)
Reported backfire — Asking for several options at onceAn increase of over 50% in 9% of scenarios. Don't use it on questions with one right answer
Where these figures come from
We read the prompt to see whether it carries that instruction. The percentages below are published figures for the rule itself, not a measurement of what this prompt saves.
Specifying output length
38.7%mean reduction · 95% CI 29.7–47.7%
Podder et al. 2026 BP#5 · 18 use cases / 57 prompts
by modelGPT-4o 35%Command R+ 49%Mistral-7B 32%
Reduced in every scenario. No backfire reported
Asking for several options at once
36%mean reduction · 95% CI 25–47%
Podder et al. 2026 BP#1 · 22 use cases / 71 prompts
by modelGPT-4o 50%Command R+ 44%Mistral-7B 39%