I've been doing IM about 3 years now (18 months full time).
It took me the first 18 months to start making anything at all and then I've really scaled up since going full time now I've started building a business out of it.
$100 is more than possible, but it will probably take you a year to hit. Once you can do $100 a day consistently, you should be able to scale up.
I'm not even close to being a top earner, but I'm aiming to hit 7 figures in profit in 2012 (between myself and business partner) and I'm not expecting to land too far short.
Great insight! I think it really comes down to learning. You need to be able to learn and learn fast. Don't fall back into the same mistakes you have done before. Really understand what you did wrong and move on. You are going to lose money no matter what, but be smart and limit the money you have to lose in the beginning. Don't set out to lose money, but just know it is there.
I lost about a whole year on my first site when I thought I was going to be a millionaire. I lost a lot of time and money but one thing that I did not lose was the experience and everything I learned. It also made me confident because I knew that I could fail and fall down and get right back up and be ready for more. You will find out real quick if IM or business in general is not for you.
Fail real hard and if you are still around, then you know you were destined to do it

Also, be confident in what you are doing. The more you learn the more confident you will be and when things don't go your way, your confidence will stand in the way of those obstacles and shoot them down.
Just because you stumbled upon IM and entrepreneurship, does not mean that it exactly for you. I knew many friends of mine that quit a long time ago because they couldn't hang.
So, to answer the question. I am not exactly there yet, or maybe I kinda am but it isn't easy but it is not that hard. It just takes patience, persistence, a great drive to learn and succeed and a little brain power