200 science posts on 100 days (2 posts a day or 1 post one comment a day).
Original title (no copy paste)
Original couple of lines of description (no copy paste)
Should be a topic that interest you and you know about to make a good comment/description.
You should have read the original article (not post blindly).
Make the site lively by commenting, posting, voting...
40$/200 posts
The quality is more important than the quantity.
Try to select local topics or topics that you personaly know about.