Sending an sms for any account , if needed in future won't create a backdoor for this kind of verification ? I am also interested to know if I could offer 0.4 usd per SMS verification then what will be the quantity of numbers you would be able to provide per day ? Let me know if you provide in bulk .
Yes. I do provide in bulk. You offer 0.4$ for what service exactly? Instagram, facebook, twitter.
As a note, i am using a 3rd party for this, so yes, this could indeed be used as a backdoor by them. - I have zero control over the number itself -, although i think this is highly unlikely, however, if you don't trust it, don't use it. I can't garantuee anything, but chances are very slim.
I have over 300 numbers available for most of the sites.