If you didn't get the opportunity to spend Valentine's Day with a significant, not-so-significant, or anonymous other, you could choose to lay the blame on where you live. According to Facebook's "Data Science" team, the cities with the most single people per capita are Detroit, Los Angeles, New York, Miami, and Memphis.
Since Facebook claims to have used only anonymized and aggregated data, however, we can't know if those people opted to be single or are simply unloveable. Similarly, Facebook also lists cities with "the largest probability of relationship formation for a single person," but it doesn't explain its methodology nor does it give us any figures. El Paso might indeed be one of the best places for single people to find love (also, killer tacos), but, based off this chart alone, we can't know if the difference between, say, San Antonio and Colorado Springs is as significant as it looks.
Facebook also breaks down the most single females per male by city, and vice versa, but that doesn't necessarily mean those people are eligible for the opposite sex. San Francisco is the top city for single males per single female, but you could argue that its numbers are skewed because of its higher population of gay men. Then again, we weren't given real numbers, so we can say anything we want.