When you're unusually secretive about what you're up to and refuse to answer their direct questions, they'll stop texting you.
If you make them feel like they're bothering you, they won't reply to your texts.
When they run out of things to say and realize it's up to them to keep the conversation going, they'll stop texting back.
They won't respond to your texts if you always say the same thing and ask the same questions.
If you make them feel bad about liking something that isn't to your taste, they won't text you back.
When you never agree to meet up in person and prefer to keep the chemistry between you solely via phone, they will stop responding to your texts.
When you take too long to respond to their texts and the conversation stalls, they will stop texting you back.
When you aren't as playful as they would like in return, they may stop texting you.
If you never text them first, you're asking for them to stop responding.
If you have too many typos and they can't understand what you're trying to say, they won't bother texting you back.
When you make every conversation s*xual and destroy any chance of having a casual exchange, they will stop responding to your texts.