Harvard professor and self-proclaimed web advertising guru Ben Edelman claimed in a blog post that customers paying for ads on its video search engine site were being scammed.
He said the website had “low-quality traffic, low-quality content, and invisible ads”.
The company responded to the claims and the share price slide in a stock exchange statement: “Blinkx strongly refutes the assertions made and conclusions drawn in the blog post.
“The company confirms there has been no material change to the operational and financial performance or outlook for the business, and that Fiscal Q3 trading was in line with management expectations.”
It highlighted a phrase at the bottom of the blog post, which points out that the consultant was paid for his efforts: “I prepared a portion of this article at the request of a client that prefers not to be listed by name.”
Edelman first directed readers to his blog on Tuesday on Twitter, saying: “Video ads begin when user leaves. Sneaky adware cheats advertisrs [sic].”
The shares jumped almost fourfold to 227p, but they have been in steady decline since the New Year.
Investors were left nursing a 50% fall at one point on Thursday, recovering slightly to 113p.