I wonder whether it depends on the topic area as well, and travel may be more competitive as there is a lot of content in this field, and a fair few nominating pubs now.

Since my pub, Iberospherical, joined the programme at the start of last month, it's seemed to me that when I nominate stuff from my own pub that is firmly within my topic area of hispanic sociocultural background, rather than travel, the approval rate has seemed higher than if I stray a little outside that area and nominate self-published stuff from elsewhere that would be more 'travel' or 'memoir'.

But you can just never tell what it was (probably a combination of factors) that meant a story was accepted or rejected.