@Priest:
If you will notice that many of the books on the list put out by Goodreads are by Goodreads authors.
I'm not sure I understand you correctly.
"put out by Goodreads" ? Goodreads don't publish these books. It's a social networking site for book lovers. And because the M/M following on Goodreads like I've said is huge, this may account for why many M/M authors also have accounts on Goodreads, which makes them "Goodreads authors".
If you're referring to the list and how many of the books listed are by Goodreads authors, it should be noted that Listopia lists are created by members where regular goodreads members as well as goodreads authors can vote for books to get them higher up on the list. Book ratings come into play here too I suppose, BUT it's Listopia votes the books need in order to climb. That is to say that Listopia lists are more like a popularity contest, and so having a massive group of supporters willing to vote for a particular book is mega helpful.