Here's a list of the different ways users can subscribe to campaigns in Contact Reach:
Text-keyword - probably the most commonly used subscription method in Contact Reach. This only requires users to text the "campaign keyword" to the "campaign number" to subscribe to the campaign. After texting, they'll receive the Keyword Message where the link to the campaign form can be placed so users can input the rest of their info (based on the form) and be recorded into the system.
Campaign Form - the campaign form can be placed as a "merge tag link" (i.e. %form%) on the Keyword Message or shared directly with customers.
QR Code - the QR code is something that you can grab from the campaigns list for each campaign and print on the business' receipts, table tents, etc.. When scanned, it redirects customers to the campaign form.
Scan to subscribe - this option generates another QR code for a campaign but instead of redirecting users to the campaign form, the code sends out a command to the phone (used to scan) to open up the messaging app, create a text message that contains the "campaign keyword" and populates the number field with the campaign number - so all a user need to do afterward is to "send" the message - which makes it a "text-keyword" subscription
Click to subscribe - the same outcome as the Scan to Subscribe but instead of a QR code, this option contains a "code" that you can link to a website button. When users tap on that button using their phone, the code will also send a command to their phone for the subscription - the same as the scan-to-subscribe method.
Embed HTML & Iframe code - these options contain a code that you can place on your website as HTML content. The content will display the actual campaign form making it easier for website visitors to subscribe to the campaign as they don't have to text the keyword or tap a button to go to the form anymore.