Keyword research is an important part of your SEO campaign, its very important to select right keywords to target, because selecting wrong keywords will lead to nothing but your efforts and money will go in vain. I have seen that people often select too broad keywords, having too much competition. In my opinion you should select such keywords only when you are a big corporation and you have a great fan following who love to talk about you, because it will lead to automatic link building which is very essential while doing SEO.
Recently I came across one question which was like this:
I want to get the SERP of the keyword “iPhone application development”. Back links for this page is 27.
when I searched "iPhone application development" I saw that websites which were coming on top were having very good backlinks. So my opinion on this was:
In this competition should also be taken into consideration. If you search for “iPhone application development” on google.co.in (considering that you are targeting Indian market) then the first website which we are getting has the targeted keyword in the url itself and they have enormous backlinks too. So, if you are a start up its very difficult for you to rank for such a broad keyword in a short span of time because your competitors might also be doing SEO on a continuous basis and more over they might be having a good and satisfied clientele who might be active on social networks giving backlinks to your competitor.
So my recommendation for you is to make a good back linking strategy, start building links on a continuous basis and target other keywords too along with your broad search term "iphone application development". You can also use social media to your advantage as you are iphone apps developer.