You will get listed eventually. It does take longer than it use to with Google. However, there are now over 8 billion pages in their system. I remember when they cracked the 1 billion mark and that wasn't that many years ago. Most crawlers can only fetch around 10 million pages per day. I'm sure the major players are doing much better than that, but even if they can fetch 100 million pages per day, many of those request are going to be looking for pages and rss files that have changed, not looking for new unlisted pages. I'll bet half their capacity is devoted to refreshing present content and the other half to looking for new pages. This is all just a guess, but math is math and there is only so much they can do in a one month period of time.