Slack After Eighteen Months of Salesforce: A Quiet Erosion

Eighteen months into Salesforce ownership, Slack is the same product it was in 2022 plus a Salesforce sidebar. That is the entire story, and it is more interesting than the trade press has acknowledged. Slack pre-acquisition was the most product-led-growth-shaped enterprise software company of its generation. Slack post-acquisition is a Salesforce module. The roadmap is set in San Francisco, but for a different audience now.

We tracked Slack's product velocity across the 18 months since the acquisition closed and tested the current product against Microsoft Teams and the smaller-but-credible alternatives (Twist, Zulip, Discord-for-business attempts) at four operating teams over Q1 2025.

Where Slack still wins

Core messaging and search. Slack's message store, search performance, and the ergonomics of finding old conversations remain meaningfully better than Teams. For an organization where the chat history is a real institutional asset — and it is, for most modern knowledge-work companies — Slack is still the better tool.

Slack Connect (the cross-organization channel feature) has matured well. It is now the right answer for most B2B vendor-customer or partner-collaboration use cases and has compounding network effects we did not fully appreciate two years ago. This is the one Slack feature where the post-acquisition team has shipped meaningful new value.

Slack pre-acquisition was the most product-led-growth-shaped enterprise software company of its generation. Slack post-acquisition is a Salesforce module.

The third durable strength is the integration ecosystem. The native and partner-built integrations — particularly the engineering tooling integrations — are the deepest in the category. Teams has closed the gap on first-party integrations but is structurally behind on long-tail third-party ones.

Where Slack has fallen behind

AI features are the clearest case. Microsoft Teams Copilot has shipped meaningful, daily-useful AI features at a faster cadence than Slack's Einstein-branded equivalents. Meeting summarization, channel-summary, and inline assist are noticeably better in Teams. Slack's AI is technically present and is shipping, but the velocity is visibly slower than Teams's. That is not a temporary state; it is a strategic decision about where Salesforce wants to spend AI dollars.

The Salesforce sidebar is a small product detail and a large strategic signal. The visual integration of Salesforce records and panels into the Slack interface is, from the perspective of a non-Salesforce-using team, an unwanted feature. From the perspective of the joint-customer thesis, it is the entire reason Salesforce paid $27.7 billion. The user who is not the joint-customer is now experiencing a product subtly tilted toward someone else's needs.

On pricing

The Slack price escalation has been the most aggressive in the category. Pro tier increases of 10–15% per year, Business+ in similar territory, and Enterprise renewals that have come in with double-digit increases on a per-seat basis. The pricing changes are not, individually, outside the band of normal SaaS escalation. The cumulative effect over three renewal cycles is substantial.

We have heard from multiple buyers that renewal negotiations have hardened. Discounts that were available two years ago are no longer available; multi-year price-lock provisions are harder to extract; the AE relationship is more transactional. This is consistent with the broader pattern at Salesforce-owned products.

What to do

For organizations on Slack today: stay, but renegotiate aggressively at next renewal. Push for multi-year lock pricing with a defined cap on annual escalation. Demand transparency on the AI-feature roadmap. Insist on opt-out for the Salesforce sidebar.

For organizations evaluating: Slack is still the better product than Teams for most knowledge-work companies. The decision is closer than it was. If you are a Microsoft 365 customer with no incumbent Slack footprint, Teams is now defensible. If you are a Slack customer, the migration cost is real and the alternative is not dramatically better.

The verdict

The product is still good. The trajectory is the worry. Eighteen months in, we are watching Slack the company become something different from Slack the product. The product team is still capable; the strategic pull is in the wrong direction. We hope the next twelve months produce a different review. We are not optimistic.