Receiving iMessage on iPhone from iPad without iMessage turned on

Hi--

I have an iPhone, and do not have iMessage turned on. Is it possible for someone using an iPad/iPod touch to send a message to me via my phone number? According to this page:

http://www.imore.com/how-send-imessage-your-ipad

under the section "How to send a text message with iMessage on iPhone, iPod touch, and iPod", #6, it seems to suggest that you can, that the send button will turn green on the iPad/iPod touch and it will send as a SMS message instead. However, when I tried this from my iPod touch it did not work. I entered my phone number as the recipient (formatted +1xxxxxxxxxx), and it turned red, and the send message doesn't light up at all.

If I go ahead and turn on iMessage on my phone, then it works, but of course then it is just sending it as an iMessage.

Thanks for any clarification.