We wrote two days ago about Microsoft touting the rapid growth of their enterprise collaboration chat app, and then yesterday on Slack’s response touting better engagement.

Today Slack has made a rather less dignified attack on Microsoft, complaining in a rather whining fashion about Microsoft copying one of their ads.

Touting their Millenial credentials against Microsoft’s maturity, they certainly came across as somewhat desperate. The company’s share price is currently close to half of their IPO price earlier this year, and they lost nearly 10% of their value in one day when Microsoft touted their latest user numbers.

The ads are obviously very similar, but Microsoft has made no secret that they are going after and marketing against Slack, producing this chart for example.

Dear Slack:  Desperation is an ugly look 1

The ad is very likely designed to place Microsoft as a clear alternative to Slack, and complaining about the design is like complaining about the coke ad looking similar to a Pepsi ad.

Slack CEO Stewart Butterfield has previously accused Microsoft of “surprisingly unsportsmanlike” behaviour, saying their active user announcement was made in June during Slack’s pre-IPO quiet period, meaning they were not able to respond.

Recently Slack finally did respond, insisted its users were more engaged, and because Teams was bundled with Office, Microsoft’s numbers were “a little bit misleading in terms of what you’re measuring.”

Slack complains about Microsoft ad may be the best headline the company can hope for, and they do not appear to be generating much sympathy from users, especially in the wake of their rich text editor update which is being very poorly received.

As one commentator notes, Slack complaining about being copied is pretty rich for a company which put a front end on an IRC client.