Thanks for the heads up
So, you willing to help me out with your 8+ years experience?
My dear friend, this is the reality...!Way back in 2007 2008..I used to find long tail keywords, create niche sites like you did and then get few backlinks from ezinearticles and other web2.0 properties and it used to rank.. Back then there were also some blog networks which gave you backlinks on a monthly costs....
see one such site I've created 2.5 yrs ago and I tried selling it on flippa but it did go unsold..!The site was created in Drupal..!
https://flippa.com/2824736-selling-my-website
But after penguin, panda, EMD updates Google has stopped giving value to such things and deindexed most of these blog networks.... Now if you want backlinks you should get them from relevant sites.. For a single such backlink the website owners charge around 40 USD/month to 80 USD/month..... Are you ready to get 10 such backlinks..? If you do that your site will rank (again based on the competition level). The next option is PPC....
I would suggest the best option is PPC these days.....
So the question is what budget you have for each niche site..... If it was me I would have a budget of 900 - 1200 USD just to test the product(wait for 10,000 impressions, then analyse the CTR, conversions, and to calculate the epcm)If I get a positive CTR and conversions I would then spend 100 USD to 300 USD each day and advertise your ad on that advertising network....!!!!!!!!
So in short getting traffic is not about SKILL alone.... it is how much money you have?????....I can create a multi-niche website, have a content locker created in PHP in about 5 to 6 hours....?????
Had you said... "this is budget I have", I would have given you the correct answer..!