What\'s Next for Tumblr and Instagram

David Karp, the chief executive of Tumblr, and Kevin Systrom, the chief executive of Instagram, gave some hints Monday about where their services were headed or not headed during interviews on the stage of the GigaOm Roadmap conference in San Francisco.

Mr. Systrom, who recently sold his photo-sharing site to Facebook, said he was not too worried about Twitter adding photo filters to its service. Instagram owed some of its success to allowing people to change the look of photos with filters, he said. “Filters are pretty ubiquitous at this point,” he said.

He said he did not expect an Instagram for video anytime soon either from Facebook or an upstart because data speeds were too slow for people to post quickly and download quickly to watch. He also said that unlike still photos, videos took time to edit and were difficult to flick through. “Someone is going to work on it and do it very well,” he conceded, though.

Mr. Systrom said his company was working on ways to mine photos so users could find important or relevant photos quickly. For instance, he said people uploaded 800,000 photos with the hashtag #sandy during the big storm last week. That was about 10 times the number of photos from an event like the Super Bowl. But users would have difficulty finding specific photos because they were a jumble of people drinking wine, trees down on cars or gas stations with gas.

Om Malik, the founder of GigaOm and the interviewer, called it “data dissonance.”

Mr. Karp, who founded the blogging service Tumblr, talked in depth about why his service did not provide a mechanism for commenting on Tumblr sites. He said the absence of such a mechanism was intentional, to prevent nasty comments. He said comments on most sites mad people feel like second-class citizens. “It makes you feel like you have to speak in all caps,” Mr. Karp said.

Instead, the company offers “fan mail,” in which a person sends a r esponse to a Tumblr author with an electronic postcard that the commenter designs. The commenter also designs the stamp and the background and chooses a font. Mr. Karp said that by the time a user spent 40 seconds or a minute doing that, “anything nasty you want to say is diffused.”

He said that no one had really figured out how to conduct meaningful and pleasant conversations online, but that he wanted to try to solve that difficult problem.