Please don’t force browsers to show a warning message that could freak shoppers when they land on your site. I saw this when I visited halfpricedrapes.com from my desktop computer—
Without even seeing actual opt-in rates for this pop-up I can bet it’s less than 15%. And the 15% that do allow halfpricedrapes.com to know their location probably click it by mistake. If you’re going to try a strategy like this please either A/B test it or annotate the date of change in Google Analytics and measure bounce rate metrics for the first week. If you see a 10% spike in bounce rate it’s probably due to this location request popup.