Seminar Report
MarkeZine Day 2026 Spring Presentation
What Is Effective Email Marketing to Increase Leads?

Last Updated:
March 26, 2026

This is Tozaki from the uSonar marketing team.
On March 4, 2026, I joined a session at MarkeZine Day, hosted by Shoeisha, alongside our Executive Officer from the Sales Division, Yuasa.

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In this session, we discussed the themes of partial optimization versus holistic optimization in B2B marketing.

This article provides an excerpt from the session.

B2B marketing is a field that can easily fall into the trap of partial optimization if one is not careful.
This often happens because marketing department goals tend to be siloed within the department itself, making it difficult to achieve company-wide optimization in collaboration with other divisions. However, even within marketing operations alone, partial optimization is a common occurrence. Let me provide an example.

One of the primary tasks in B2B marketing is lead generation.
I am sure you are all acquiring leads daily through various channels such as trade shows, content marketing, and ad operations.
But in reality, are your usable leads actually increasing?

Of course, since you are actively acquiring leads, the total number of leads is likely increasing.
The issue is whether the leads that the marketing department can actually utilize—that is, leads that can be used for email marketing—are increasing.

B2B marketing relies on email as a vital channel.
By conducting appropriate email marketing, you can maximize the effectiveness of various initiatives.
However, as is to be expected, a certain number of unsubscribes will occur when sending emails.
This is where the pitfall of partial optimization lies.

For example, let us assume a marketing department at a company holds a house list of 50,000 contacts.
This company acquires an average of 1,200 new leads per month through events, advertising, and WEB traffic.
This totals 14,400 leads annually.

They are also focused on content creation, sending out a weekly newsletter featuring their latest content.
Furthermore, they host webinars twice a month, sending out three promotional emails for each webinar.
This is a company that actively practices lead acquisition, content creation, email marketing, and webinar hosting.
If we assume an email unsubscribe rate of 0.2%, will the number of leads in this company's marketing department actually increase?

Example of Adverse Effects Caused by Partial Optimization.png

In reality, the list only grows by about 2,000 contacts per year.
While it is growing, considering they acquire 14,400 leads annually, the growth is likely less than expected.
If this is continued for one year.png

As the size of the house list grows, the number of leads lost increases even if the unsubscribe rate remains the same, so the list does not grow as much as one might imagine.
In the worst-case scenario, for every few dozen people attracted to a webinar, hundreds of people may be unsubscribing in the background.
Under these conditions, the effectiveness of marketing initiatives will never improve.

To avoid these issues, it is necessary to implement segmented email delivery.
While segmented delivery is often associated with narrowing down targets to increase response rates, it also serves the purpose of protecting your house list by ensuring that irrelevant emails are not sent.

At uSonar, we also perform appropriate segmentation when sending our own emails.
As a result, recipients no longer receive emails that are completely irrelevant to them, which has successfully reduced our unsubscribe rate significantly.

Recommended Segments.png

For reference, while our total email volume increased by 23% in 2025 compared to 2024, we were able to reduce our unsubscribe rate to 70% of the previous year's level.
By increasing the number of leads with whom the marketing department can communicate via email, we can create a virtuous cycle where email marketing performance continues to improve.

In the actual presentation, we provided deeper insights, such as how to perform segmented delivery that yields results.
If you are interested in segmented delivery using the corporate attribute data provided by uSonar, please feel free to contact us.

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Author

uSonar Editorial Department

MX Group Editor-in-Chief

We are the uSonar Editorial Department.
We provide information on data utilization and digital technologies useful for companies primarily engaged in B2B operations to rethink their future business practices.