Is another person necessary to produce merit? Can someone produce merit without impacting directly another person? For instance: Meditating alone.

I appreciate all answers but I'm more curious about Theravada view. While meditating with Tibetan teachers (Mahayana) they did mention meditation alone can create merit.
From Iti 60:


  This was said by the Blessed One, said by the Arahant, so I have heard: "There are these three grounds for meritorious activity. Which three? The ground for meritorious activity made of giving, the ground for meritorious activity made of virtue, and the ground for meritorious activity made of development [meditation]. These are the three grounds for meritorious activity.


And with just meditation alone, the generated peace and serenity could very well benefit many other beings with form or without form living nearby..