Do not respond to unwanted texts or emails from questionable sources. Several mobile service providers will allow you to report unwanted spam texts by simply texting/forwarding it to 7726 (or “spam”) to enable the providers to prevent future unwanted texts from the specific sender.
More info:
http://en.wikipedia.org/wiki/Mobile_phone_spam
http://blog.usa.gov/post/89152807112/protect-yourself-from-text-message-spam
However, in many cases, the text origin, as seen on your phone, is faked. The internet domain does not exist, or the phone number may have been spoofed.
"Excuse me, I don't want you to think I'm ridiculous or anything, but you are the most goegeous man I have ever seen. I just felt like I had to teell you., Text Back"