Amazon has narrowed the potential host cities for its second headquarters, known as HQ2, down to 20 metro areas that match many of its stated requirements. But there's another way to look at the finalists: More than half of the 20 cities are in states that lack nondiscrimination laws. Eleven cities, to be exact, across nine states that don't have legal protections against firing an employee based on sexual orientation. That has caught the attention of advocates for nondiscrimination laws protecting LGBT citizens.

LGBT activist group No Gay? No Way! had a plane fly over Amazon's headquarters in Seattle with a "No Gay? No Way!" banner on Feb. 1. Digital ads ran in Seattle and within the nine states, reading: "Hey, Alexa? Why would Amazon even consider putting HQ2 in a state that discriminates against LGBT people?" A truck carried a mobile billboard around Seattle with this same message.

Finalist cities are refining their pitches based on many of the factors that usually motivate corporations in site selection — economic development opportunities, transportation access and infrastructure, skilled labor force and quality-of-life measurements, like education and real estate costs. But "culture community fit" also is included as a factor in Amazon's decision-making matrix, which consists of eight "key preferences and decision drivers."

LGBT advocates are focused on Amazon's history as a progressive company that supports its LGBT employees. Read more via CNBC