Twitter looked into buying the popular photo-sharing app Instagram last year, before the 123-person company was purchased by Facebook for $1 billion, CEO Dick Costolo said during a visit to Tokyo Monday.

But the company won’t push for a similar acquisition, The Wall Street Journal reported.

“I think that sometimes there is a tendency for companies to react to events in the marketplace that are inconsistent with their strategy … and I think that tendency is a mistake,” Costolo said.

He noted how tech players rushed to buy video-sharing sites after Google bought YouTube for $1.6 billion in 2006, even though many of those bets ultimately fizzled.

“You can look at all sorts of other similar cases in the past when an event like this happens and people try to react to it. Copying it is never a good idea — at least, history would say it’s not a good idea.”

The executive outlined a plan to focus on evolving its application programming interface (API) so other companies can build products into Twitter, similarly to how Amazon.com sellers market their wars, the Journal reported.