If Post.fast_count returns nil, then the link_to call becomes link_to(nil, <posts_path>) so the link text becomes the url itself, which isn't what we want. Instead the count is displayed as a '?' mark to indicate that we don't know the true count.
If Post.fast_count returns nil, then the link_to call becomes link_to(nil, <posts_path>) so the link text becomes the url itself, which isn't what we want. Instead the count is displayed as a '?' mark to indicate that we don't know the true count.