Hi!
I am telling you about the software that is whatsapp bulksender. you can send whatsapp message upto 15000 numbers at once. This is best tool for marketing of your product, youtube channel promotion , I am also using it, Its work awesome.
Here below its links... Please watch , like aun subscribe my channel :)
https://www.youtube.com/channel/UCvxJDrykP5dtDViBGNUQkpQ
https://www.youtube.com/watch?v=lrGlt25NvI0
Regards
Shah
