I am unable to understand how signature campaign participation can affect getting merits.  Making  quality post just depends upon one's ability to express himself over the subject for which he is having knowledge.  Now if he wears signature I am sure it will not affect his writing ability.
Though nothing is free in this world, we have to pay something in return for what we receive.  Suppose I write and post some topic, my expression, presentation, message is liked by some senior ; in return he may send merit.  Though I have paid nothing in physical but the knowledge I expressed is the value I paid which could increase / satisfy the knowledge level of merit sender.
50 merits for this post          Please Share the secret behind this huge success, for  the benefit of others.