Mobile/Cell Phone Leads - Worth Collecting?

I'm running a W4M campaign right now, collecting emails to monetize. I noticed that alot of these leads are very willing to provide me with their cell phone number as well, and are doing so without me asking or saying anything about phones or texts.

So, this has got me thinking. Are these numbers that I now have access to worth collecting? Is there a market for W4M cell phone leads?

I have a method in the works that should provide 90%+ USA numbers. These can very easily be geo-targeted via area codes, and I'm working on a way to auto-verify numbers as well.

Thoughts? Ideas? Interest?

If you are still active and have leads for sale PM me or sk y pe: richymase