Video search-engine operator blinkx swung to a first-half profit as it continued to grow its audience, and announced a partnership with a unit of Amino Technologies.

Founder and chief executive Suranga Chandratillake said the number of daily searches using the company's technology had more than doubled to 31.6 million, helping generate a pretax profit of $2.0 million (£1.2 million) on revenue of $27.4 million.

"The business is strong, the pricing feels very solid, the video searches keeps growing, which is driving revenue," he said in an interview on Tuesday.

blinkx generates revenue by selling advertising tailored to the video content or the location of viewers, and is able to command higher rates than for an equivalent number of ad impressions on broadcast television.

Ad rates in the period were $16.50 per 1,000 impressions, he said, above a rate of about $15 on U.S. television.

"(Rates) were the same as six months ago, but one thing that did change was the size of the bookings. The average size of a deal grew by 40 percent. That represents an increasing number of advertisers booking larger, more consistent campaigns in video advertising," he said.

"People are adopting online video as a standard thing they do alongside television, newspapers and Internet search."

He said he expected ad pricing levels to remain flat going forward.

Under the terms of partnership, the company's technology will be deployed on Amino's hybrid set-top boxes that take both internet and TV-signal feeds.

blinkx, which was spun-off from software firm Autonomy, said it had new premium content partnerships with BBC and AccuWeather during the period.

Shares in the company, which has indexed audio, video, viral and TV content and made it searchable and available on demand, have more than doubled in the past four months. They were 0.3 percent lower at 1200 GMT.