Depending on the services you offer, you may be better off if you move up the free line. That's what we have done a couple of weeks ago, and (so far) we have no reason to regret our choice.
For ages authors have sent their manuscripts to publishing houses without paying a dime for the time and money it took to read them. The stamping costs prevented the authors from bulk-mailing. Things were well balanced: a good manuscript paid for the others.
Then the internet allowed publishers to look for authors anywhere in the world, which was a major breakthrough. But it allowed so-called authors to submit so-called manuscripts to dozen of publishing houses.
Since nobody could afford missing the next Da Vinci Code, and there was absolutely no means to foresee which manuscript would be the next winner, the increasing of reading costs was fantastic. Of course, vanity publishers did not mind the costs: the more manuscripts they received, the more payers they found.
A many reliable publishing houses had to step back to traditional mail. We'd rather put a price tag on our service.
We bet that genuine authors would trust their own works enough to pay for them to be read. Then, we feared a lot: a one dollar price tag had been heavy enough to halve the number of "submitted manuscripts". We examined the results closely: the spamming had disappeared (no more ads for blue pills, watches or naked girls in our database), but nothing else had vanished.
We increased the price dollar by dollar, until we stopped receiving the unworthy stuff that prevented us from focusing our efforts on valuable manuscripts. We may have lost some good authors in the process, but on the whole, moving up the free line has proved to be advantageous. The strategy cannot apply to any business. Nevertheless, before following the common stream and moving down the free line, be sure you should not move it up.