Scam or True gimmick?

Today i received a sms from
SMSCaster.com(sender no:0162184633)
which the site is using Bulk SMS Text Messaging Software for Mobile Marketing!

"slmt sjthra anda ditawarkan set decoder astro free pasang rm100,t&c apply berminat sila sms
nama,ic,alamat or call 0163623748(khaty)"

Well i didnt reply back and what i piss most is that..how in the hell,they get my phone no?
Anyone out there too received this?.......