m planning to start a new blog using sony as my niche. i want to know that is it profitable niche or not?
You would be better off narrowing your niche further, such as Sony laptops or Sony televisions. Use the Google Adwords Keywords tool if you don't have a better tool such as Micro Niche Finder.
Check how many sites are using Sony as their niches and then try to find out whether its been a profitable niche for them or not if yes you can surely go ahead and if no then you know the answer. also, the success/failure of a niche depends on how much you are going to put into it take help of Google's adword tool to find out monthly searches related to Sony and try to focus on low competition keywords if you are moving ahead with this idea
Sony will want you to pay them $2000 per month so your $1 per month earnings with that site will hurt you quite a bit.
Sony is a well-sized Niche. There will be enough stuff to allow you to add new content everyday, but not too much boring stuff. In addition, a good time to start would be NOW because the NGP (PSVita) is gaining popularity and will go up in Google Search Rankings very prompty. I have a recently launched sony-related domain I am willing to sell, along with the site and content. PM me if you are interested