Hey OP I just wanted to chime in, and please don't take this the wrong way but if you are solidly working for 12 - 15 hour work days on IM on a daily basis you should in theory see results with in 2 to 3 months, sounds like you may have poor time management skills, like me when I first started.
I thought I was working 12 - 15 hours a day but I really wasnt, I was easily distracted by facebook, twitter youtube and whatever other internet distraction gets you from being productive.
I made a plan for what I should be doing form day to day, regardless of how I felt I managed to get shit done. in this business you are easily distracted by many things and you'll easily find yourself doing nothing, from this simple change I saw results coming quicker.
Also being in IM I think most people spread themselves thin across too many projects which starts the repetition of constant start and failures, start with one project and focus on just that and make it as good as you possibly can, test new strategies and techniques all the time change stuff around and just tweek and tweek until you get some better results, you will be really surprised.
Never stop trialling and testing:
As an example: one of my high ranking sites fell in the serps significantly cutting my sales 80%, for a month I was like 'WTF' and I was just reading and testing just to get some more ideas as to handle the problem. All of a sudden a possible solution jumped into my head! I ended up just changing the permalink structure of my site and automatically i started seeing my site rising up in the serps back to where It was originally.
Cover all your bases, literally! use Social media, on page and off page SEO, email marketing, forums, guest posting, PR posting and etc, these are all tools which will benefit you and will go hand in hand with all your projects, never look past them and try to do them all.
Most people just do SEO and it works for them, for me I do everything to promote a site, after all the key is to make it as natural looking as possible so all your hard work is not going to be taken away from you in one google update.
Read, learn and take action: read and learn as much as you can and apply it to your own projects, read blogs and forums like BHW, maybe rip a few WSO's which relates to you.
You may not have the right mind set, maybe you should try to get your hands on some motivational speaker videos which can relate to you. Try Jordan Bellforts video course, the motivational side is awesome and significantly helped me with my progression.
That all being said, you have to do the ground work before jumping onto a project in IM, im not going to go into detail here as other members have already covered this aspect in your thread but doing Keyword research and measuring up your competition is absolute KEY. Not knowing how to do this and ignoring this important aspect you are gambling your time and money and you will certainly set yourself up to fail.
I hope this helps and never stop reading and learning, all the best
