13 posts and 7 merits. Your posts are too high quality (it seems because I don't know your local language, I guess based on what you wrote in English and length of your posts in local board). Length of post does not guarentee post quality, but it seems you made quality posts, too higher than other newbies.
I don't think you are new here.  

Some things managers likely consider when screening applicants to choose participants:
- Post history to check post quality
- Trust Flag history
- Language: mixture between English and local; or purely English
- Average posts per day/ week
- Inactive or active posting in recent weeks

There's no general answer to that, because each campaign manager has his own standards.  Basically if the manager cares one whit about this forum's quality, he won't choose people who consistently make garbage posts.  Unfortunately there are managers who don't care, and they have to fill up the campaign with participants--the result is that you get very low-quality posters making a huge amount of nonsensical crap posts. 

The bitcoin-paying campaigns are generally run by good managers like Yahoo62278 and DarkStar_ (though they aren't the only good ones), while altcoin/token-paying bounties tend to be run by managers with low standards.  At least that's my observation.