Is your pickup rate plummeting? Going from 12% to 4% in a few weeks? There's a good chance your numbers are marked as spam. Here are the 5 mistakes that kill your telephone prospecting campaigns.
Mistake #1: Too Many Calls Per Day on the Same Number
The Problem
This is the most common mistake. A number making 200, 300, or 500 calls per day immediately triggers detection algorithms. According to Skipcall, a number can be flagged as spam after just a few days of intensive use.
The Solution
- Limit yourself to 50-80 calls per day per number maximum
- Use a sufficient number pool to spread the load
- Rotate your numbers throughout the day
Mistake #2: Ignoring Legal Hours
The Problem
Calling before 10am or after 8pm, on weekends or holidays is not only illegal, but it's also a strong signal for anti-spam algorithms. Off-hours calls generate more reports.
The Solution
- Strictly respect 10am-1pm and 2pm-8pm slots, Monday to Friday
- Program your dialers to automatically cut off outside hours
- Watch out for your prospects' time zone!
Mistake #3: Calling the Same People Too Often
The Problem
Calling the same prospect 5, 10, 15 times in a few days is the best way to get reported. Each unanswered or hung-up call increases the likelihood of a report. The law also limits contacts to 4 times maximum per month.
The Solution
- Respect the 4 calls maximum per month rule per prospect
- Space your attempts several days apart
- After 2-3 non-answers, switch to another channel (email, SMS)
Mistake #4: Using "New" Numbers Too Intensively
The Problem
A brand new number that starts making 100 calls/day from day one is highly suspicious. Legitimate numbers have a progressive call history. A new number with no history that suddenly starts calling massively is a red flag.
The Solution
- "Warm up" your new numbers: start with 10-20 calls/day
- Gradually increase over 2-3 weeks
- Mix outbound and inbound calls if possible
Mistake #5: Not Letting Your Numbers Rest
The Problem
Using the same numbers every day, all year, without pause, inevitably wears them out. Even with reasonable volume, the accumulation of micro-reports eventually reaches the critical threshold.
The Solution
- Apply rest time between campaigns
- Rotate your numbers: 1 week active, 1 week rest
- Watch for warning signs (declining pickup rate)
How to Know If Your Numbers Are Blacklisted?
Telltale signs:
- Plummeting pickup rate: going from 10-15% to less than 5%
- Many immediate hang-ups: prospect sees "Spam likely" and refuses
- Negative feedback: "I was told it was spam"
To check your numbers' status, use a reputation verification service.
Best Practices Summary
| Mistake | Limit to Respect |
|---|---|
| Call volume | 50-80 calls/day/number max |
| Hours | 10am-1pm, 2pm-8pm, Mon-Fri only |
| Prospect frequency | 4 calls max/month/prospect |
| New numbers | Gradual ramp-up over 2-3 weeks |
| Rest | 1 week regular pause |
FAQ
How long does it take for a number to get blacklisted?
With very aggressive behavior, a few days are enough. With moderate but constant volume, expect 2-4 weeks.
Can a blacklisted number become clean again?
Yes, but it's long (several months) and not guaranteed. See our article: can a blacklisted number become clean?
How many numbers do I need to prospect safely?
It depends on your volume. See our guide: how many numbers for prospecting.
Sources: Skipcall, Cybermalveillance.gouv.fr, CNIL
