Do any ads sent by mail change any votes? I wish so many resources were not wasted with this effort. I wish there was a way to opt-out, if only for environmental reasons.
Now campaigns are resorting to sending texts constantly. This is very annoying too and a waste of resources as well.
Of course it works. Well organized campaigns have extremely granular voter data and can target with surgical precision.
If it makes you feel any better, sending text messages is practically free, both financially and environmentally.
$100 lets you text around 20,000 voters in a couple of seconds. Your average congressional district has maybe 400,000 eligible voters, so you could theoretically text every single one of them for about $2,000, a couple of hours worth of your campaign payroll.
And in terms of wireless resources, SMS costs next to nothing. This is why authorities ask people to use text instead of voice/data in natural disaster situations.