Why link building with same concept niches are important for SEO?

I see a lot of peoples pinging with me in Google talk and requesting me to link building with them these days and all they asked the same Question that is

Is your site is travel related niche; Do you interested to link building with me?

just replace travel with real estate, gardening, technology and too many, I have received numerous Emails or requests while pinging with them that related with same link building concept these days, I got confused and asked a question on my inner mind that why these peoples are willing to link building with same concept peoples, So today I  am going  to discuss with you,

Is there any beneficial ways to link building with same concept blogs?.

First of all we consider why link building with same niche is important and is there any specialty on that, Yes there is some specialty if you swap links with them.

Let consider if your blog is SEO concept and you have link building with gaming niche, then how it will be useful to build back links and traffic, If visitor sees your link which you have built with gaming niche and how he/she tend to click that link. Let consider practically if you are a gaming user, you would like to search gaming related sites and you never heard about SEO then how you tend to click that link? Same concept apply when link building and if you get benefit from your linking page either it will be useful for your site ranking and at least you can earn some decent traffic from it, all these are possible by link building with same niches.

So before exchanging links, Make sure that you will gain benefits from same concept links that related with your niche concept.