This is what all spam-distribution platforms say. Nobody ever says "we spam people."
A spam distribution platform is not a defensible business. In a year someone will come along that does it better and cheaper. There is just no long term value.
If the recipient explicitly asks you (or your partners) to text them this and that, and you text them this and that, you're not a spammer. Anything more and you've become a spammer. Seriously. Not cool. Receiving a spam text costs me a postage stamp each time. Buy your own postage stamps.
"Relationship" is the word that is most used by spammers.
Kellogs imagines that we have a relationship. So does Subaru.
More of that, I don't need.
If you're not spam, how do you prohibit bulk unsolicited SMS?
Even if you aren't, if you do well then a different company will follow with different ethics.