dOOOd it's depending on how many posts you have done it already!! For example, if you wana to increase your lvl quickly you must post many blogs in your profile, also you can post many reviews for the games and uploading videos!!
You ask why the lvl goes slowly well this is obvious that each time you lvl up its becoming harder to pass it so, you need to post more and more!! So, as I said to you before posting more blogs and reviews and you will see!! Good luck!!

yeh, because you post but not that much, you need to do alot as well, not just post.

yeh, I am posting and I am still on level 7.

almost on 8 though, just be patient and post everywhere and everything.