Just 1 time post alone is enough because per 2 weeks we can only 14 activities can not be more
It is the minimum of active weeks X 14 and the total number of posts. So you would have to post at least once a day in order to maximize your activity score. Don't need to do that myself as my number of posts are well above my activity score from arguing with scammers so much the other year.
A lot of the off topic posts seem made to meet this minimum or to meet signature campaign requirements *looks below at his signature briefly and back up nervously*. I don't see this much activity in the off topic section of other forums where profile activity scores are not as important.
It is easier to post in the off topic section than actual bitcoin and altcoin threads because the topics are ones people relate to. It is way easier to state your favorite type of music than to come up with an original contribution to threads discussing coin dynamics and development every single day. I am assuming that a number of topics are created and answered by individuals with 'puppet accounts'. At least it keeps some of the noise out of the serious threads, improving the signal to noise ratio..