of their own choice preferably from within the community.
Family and cultural influence a lot in selection of a man.
Nobody would like to get a social boycott (sometime directly or indirectly)...incase of one get married outside his/her caste, religion or community, in short to get into one relationship....cause all other relations get affected.....this need some serious considerations before such acts.

Agree, we all live in a conservative society...but with globalisation this may change, May be, I am not very sure my kids will marry an Indian muslim..but due to the present education, internet culture, social environment and obligations.
While they are very well aware of being a muslim they need a boy or a girl either to be a muslim or need to get converted before marrying (if non muslim other than Ahle-Kitaab).

Marriage is NOT obligatory by Quran...It is Sunnah and One of the pleasant and preferred Sunnah to Prophet Mohammed (Peace Be Upon Him)...it is been called as 'half faith' in Islam......an instruction to prevent us from sins and illegal relationships.....and to get accepted in civilised society.

It is purely my understanding about marriages in Islam

Just a thought....
Does Islam allows Internet Chatting (on the social website such as QL) with an opposite sex?
- In my views no harm, so far within acceptable limits exchanging views or increasing understanding about a subject...but just flirting is not allowed.