B
Evidence Grade B
Graded
accuracy verified by the review judge
Safe to Cite
Recent
69%
69% -- email marked spam by subject line rate for Email recipients (2025)
69% of email recipients mark emails as spam purely based on the subject line.
- Attributed to OptinMonster with no survey year, methodology, or sample size details provided.
Attribution:
View source
Lighthouse Research Team
Last verified:
·
How we verify data →
Source verified
Evidence graded
Value
69%
Unit
Percentage
Data Vintage
2025
Entity
Evidence Quality
B
Strong, reliable evidence
Sourced from a well-regarded research firm or industry leader with transparent methodology and a reasonably large sample.
Single source - not yet corroborated
Score breakdown
Extraction
50
Source Trust
60
Citation Chain
20
Independence
30
Methodology
45
Freshness
95
Source
OptinMonster
Primary
Tier C
https://controlhippo.com/blog/email/tips-for-effective-email-communication/ ↗
Source Article
8 Tips for Effective Email Communication
Email is one of the most common ways professionals communicate effectively. By 2027, 4.8 billion people worldwide are expected to use email! However, not all emails are productive. Some are too vague, some are overly long, and others are ignored completely.
Think about it—how many times have you rec…
Original Research
OptinMonster
· Original study ↗
Methodology
Attributed to OptinMonster; no original study date or sample details provided in source.
Methodology documented
Segmentation
Industrymarketing
Cite this stat
Plain Text
Email recipients: 69% email marked spam by subject line rate. Source: OptinMonster (2025). Via Lighthouse Intelligence -- https://lighthousedata.io/data/emails-marked-spam-by-subject-line-69pct
HTML Embed
<blockquote cite="https://lighthousedata.io/data/emails-marked-spam-by-subject-line-69pct" style="border-left:3px solid #2563eb;padding:12px 16px;margin:16px 0;font-family:system-ui,sans-serif;background:#f0f4ff;"><strong>69%</strong> -- email marked spam by subject line rate for Email recipients<br><small>Source: OptinMonster (2025) · <a href="https://lighthousedata.io/data/emails-marked-spam-by-subject-line-69pct" target="_blank" rel="noopener">Lighthouse Intelligence</a></small></blockquote>
Share
Use this data in your work
Copy the citation, embed the widget, or explore thousands more verified marketing statistics -- all free.