well, it depends on users itself as we can't guess what a user is going to search for.... Take an example of "yourself" while searching on the internet have you planned that you are going to read that particular result...... most probably your answer would be no .... so you can't do anything about it what you can do is try to be in the trend like if Android is popular today and you have written an .... say article !! that has all the information is a proper and effective manner then your probability of getting caught by the search engine would be greater. I can't tell you the time it would take .... its like you keep searching for pearl in the sea until you get the one !!
As you are saying people open blogs or website blindly without any thought of growing their business ?? There are lots of successful bloggers around blogosphere.!!! Okay as you said we cant know what user will be searching for but for that we have given tools like google keyword planner, market samurai and longtail pro to get the search volumes of certain keyword for what users are searching for...!!!
look i know there are tools that lets you know what they are searching for .... its dependent upon their requirement like if i am having a requirement for "Android Application" then that tool concentrate on letting you know how others are searching for it.... but if its about blog or something then i don't think that there is any specific term (there are only 15-20% of the people who search for blogs and the blogs which are searched we the most top i mean the blog that is ahead of every thing.....) !! well let me get back to your problem what you can do with your blog is follow the change in trend writing a good article in terms of .... (you've already know) !! This is going to help you out i would take time but surely it will help you out !!