On: If you develop web apps, don't do this.

[zaidf]

Plentyoffish emailing you your password.

OKCupid sending login token'd links

Notice the trend? When you're a dating website, engagement trumps security in many cases. But if you are a bank or any service with some liability, you're probably going to play it conservative as you should.

[sneak → zaidf]

"Engagement trumps security" holds true for 99% of the sites this audience builds. There's a reason I used Foursquare as an example.