Let's see what is hotter.
How many SMS lists you are personally subscribed to?
Are you willing to provide your phone to anyone who asks?
Are you afraid of getting on spammers lists or telemarketing lists?
What do you do if you start getting too many SMS?
What if you can't get off SMS list despite numerous STOPs?
Is it easy to unsubscribe form SMS for you? How much efforts does it take?
Is it worth the unsubscribe efforts to get on the list in first place?
How many e-mail lists are you personally subscribed to?
Do you use your primary e-mail for that? If not why not?
Fear of geting on spammers list?
Is it easy to unsabscribe from e-mail list? How much efforts does it take?
If you were to choose between e-mail and SMS subscriptions which one you PERSONALLY would go for?
Just want to see the real picture which media is used more and therefore hotter.