There is no other way to receive an easy merit! You just receive it by posting something meaningful and with a sense of course.
So work hard on your posts and make them constructive to have the knowledge they can read too !. The only really difficult for us to have merit are the people who prefer to give merit for their alts or is swapper they merit to someone else to take advantage of it.
Is possible to receive merit even you are just commenting or replying in someone's post or is it only for those you post something informative to the thread? I've heard of that swapper thing, they want to exchange their merits for alts which very alarming cause they could exploit those people want to have merit. Meaning selling at a high price..