I am currently working on 5 sites, 2 in 1 niche, and 3 in 3 others. I would like to be earning $200 per site per week through advertising, I know this can vary immensely but do you think I can achieve this goal by September?
It depends on how your traffic stats are and how many of them are quality traffic. You can always have Google AdSense on the sites and start making money the easy way or you can think of making money from promoting affiliate programs.
It's hard to guess, however I think investing a small portion of your earning in effective method of advertisement and promotional activities may bring some more revenues.
For the first 2 in niche 1 theres only 1 large site that could be considered competition, the rest are small and the other site I am making in this niche focuses on a smaller segment and afaik there are no similar sites. Site 3: kind of an inbetweener, its not a new market but not a saturated market for the demographics I am aiming for Site 4: probably the most competitive niche of them all but I am interested in the topic hence my reasoning for entering a competitive area. Site 5: This one kind of covers a few market segments but there are no similar sites
While entering to a competitive area try to find what at the most your competitor miss to target or any specific unfulfilled need of specific demography.