May I please have your opinion on social media?

[Fin Moolah]

Theoretically, it has purpose in that it can bring people together and allow for superior planning and networking than can be done through other forms of communication. However, this is becoming increasingly harder and harder to accomplish due to supersaturation of advertisements, information farming, and scams.
There is cyber bullying present on social media sites, but most of it can be avoided by not adding people who are prone to performing such harassment as friends or contacts. As for flirtation, social media CAN be used as a dating service, but like planning and networking, the practice of such is more theoretical than practical.
To answer your last question, it is a matter of opinion. I think it is worse, personally, because, like you said, the words you type stay there virtually forever. That, and overall the interactions are abysmally impersonal.
I hope I helped, but I don't know if your instructor (or whoever this assignment is for) will take kindly to using Yahoo! Answers as research.