Try like this:
<?php previous_post_link('%link', __('Older posts', 'sample-translate'), ''); next_post_link('%link', __('Newer posts', 'sample-translate'), ''); ?>
No, it’s for author’s eyes only.
I don’t know about you guys, but my sales are down by 70% compared to November.
I’ve changed the name for one of my themes, and I can confirm that the old link will still work, so you don’t need to worry about this (there’s a number at the end of url which identifies your item regardless of it’s name).