We spent 3 months on the first blog, but there were two of us working on it and we put a ton of hours into it before we threw in the towel. I can’t say that there is any kind of time period that is “enough” to know whether a blog is worth it or not. It really depends on how much time and effort you put into it and what kind of results you’re seeing. Everyone’s situation will be a little different.
The answer is YES, resoundingly yes, there is plenty of room for new bloggers to make money. (Not to mention that just because there are “millions of blogs” doesn’t mean there are millions of successful blogs. People who won’t invest the time, money and effort it requires are included in that “millions” as well. Remember, blogging for profit is work!)
My understanding is that you have to subscribe/pay for the business version of Word Press in order to use any of the monetizing functions. I think you should clearly state this in this article at the beginning. I think there is a degree of bait and switch here if people are just signing up for the free subscription and then finding out they have to pay for a subscription to make money. I am ok with that, it just needs to be stated up front everywhere.
Working with advertising networks isn’t your only option when it comes to selling ads. If you end up with enough traffic, advertisers may come directly to you and ask you to place their ad on your site. You can also contact advertisers yourself. The biggest difference from the above mentioned option is that there is no middle man, which means you can set your own ad rates.