Pull quote” To submit a paper for consideration in PeerJ, authors must buy a ‘lifetime membership’ starting at $99. (You can submit a paper without paying, but it costs more in the end to publish it). This would allow the author to publish one paper in the journal a year. The lifetime membership is only valid as long as you meet certain participation requirements, which at minimum is reviewing at least one article a year. Reviewing in this case can mean as little as posting a comment to a published article. Without that, the author might have to pay the $99 fee again (though as yet it is of course unclear how strictly PeerJ will enforce this rule).”