I started a thread a long time ago trying to help Newbies and Jr. Members to rank up and get their first merit. It hasn't seen a lot of action lately. From what the other users in this thread have posted you seem to be focused on bounties and gambling-related posts only. There is your reason for not getting merits. Merit sources rarely visit those boards.
Try to act normal. Post what you are good at and help out where you can. If your only goal is to get only one merit just to fulfill a requirement for a bounty campaign people will see through that, and probably you wont get it. Become a part of Bitcointalk and give us something to read and think about in your posts.
If you want to take a look at the thread I mentioned earlier, here it is >
https://bitcointalk.org/index.php?topic=5085605.0Read and understand the rules before applying, if you decide to do so.