Why not charge to run candidate testimonials

Les Wylie, Morgantown
It seems that for every election cycle we have involving voters in Monongalia County, we see testimonial letters in the opinion page of The Dominion Post.
This appears to be nothing more than free political advertising for the candidates.
I don’t understand why the editor of this paper is not more judicious in allowing these types of letters to be published.
I suggest that if a candidate wants a particular testimonial letter published that the candidate be charged for it just like they would for any political advertisement they would run in The Dominion Post with a notice by the letter showing it was paid for by the candidate.