Not saying e-mail marketing with mobile is any more effective than with any other typical desktop traffic source. It's not. But it is a viable way of trying to get profitable with mobile when click-to-call, mobile app, etc offers are hard to find or aren't refined enough for consumers to use yet.
What you need to remember is not everyone will always check their e-mails on their phone - or even have the ability to.
Your e-mails for the most part will be read on a computer making those that entered their e-mail no different, in theory, than any other opt-in whether from your PPV efforts, etc.
Yeah, noticed that but it was after the 10 minutes you have to edit. Since you're not using double opt-in there's no "confirmation e-mail" or page anyway. So yeah you want your offer to be seen right away on the "thank you" page.
Yup, I get the point that people will be checking emails on their desktops.
The question really is whether cost-per-signup, the signup volume and ultimately effective conversion would be better on mobile than on desktop. I do not have enough data yet, but seems like getting someone to type their email on a tiny keyboard is an obstacle. Not to mention that to put an offer on mobile "thank you" page, you have to have a mobile-formatted offer, with ultimate conversion that can still take place on the device.
I for one am definitely interested in hearing about actual successes with the strategy you described.