I shop at Blaines Farm & Fleet for a few items.  Being old and weak (and lazy) when I buy bird seed in 40 pound bags and cracked corn in 50 pound bags I order online and get it in the drive through.

They text me when it's ready. 

However of late they've been texting me rather frequently with "deals" and "specials."  Too many, too often and I didn't see the usual message others include to opt out.  Many others say text 9 or text N or text stop to opt out. F&F texts didn't have that. 

On a whim when I got the last text I simply texted back, STOP.   Moments late I received a reply that they were sorry to see me go and had unsubscribed me! Sometimes things are simple.