One of the quickest and easiest ways to collect phone numbers and grow your subscriber list is to create and promote an SMS keyword for a short code. Your customers can text it to your number to subscribe to future updates. When you create a keyword, you'll also get the opportunity to write an autoresponse that gets sent to a subscriber after they've texted the keyword to your number.
You can receive messages on a shortened number instead of a long cell phone number.
You can setup autoresponders (automated responses).
Your SMS shortcode keyword operational 24/24h, 7/7 days.