United via their MileagePlus Shopping Portal is running a Valentine’s day promotion where users who signs up for their newsletter receive 500 bonus United miles. Go here to the promotion page to check out the details.
It’s not clear if users who are already signed up on their newsletter will get the miles or not, but it’s worth your 5 seconds of clicking just to see if you’ll get a nice surprise later. Miles do not seem to post instantly. I would allow for the normal 6 to 8 weeks that United usually says miles take to post.
I value United miles at $20 for 1,000 miles. So this could be an easy $10. Get at it!