Apparently earning 76 British Airways points per dollar signing up for a dating site was legitimate, but an advertised short-term offer of 150 miles was ‘invalid’.

Scott McCartney in the Wall Street Journal takes a look at the mileage-earning deal’s demise.

Match.com and eHarmoney reneged, with Match claiming the affiliate shopping portal’s promotion was unauthorized and eHarmony saying that people signing up violated their terms and conditions — “married travelers signed up and others created multiple profiles”

Frequent-flier discussion boards went nuts over this promotion. Some travel nerds wondered whether dating services might be counterproductive to mileage accumulation, since actually finding a partner meant booking two tickets. Others wondered why dating sites didn’t let you search for mates by their airline status level. Some debated registering their wives.

Whenever there’s a great deal the first question to always ask is, how does this scale? And British Airways allows family pooling of miles across 7 accounts.

Still, I’d venture a guess that not everyone doing the deal was married with 7 accounts. British Airways says “says points earned on valid transactions that met terms and conditions will be honored.” I guess you have to prove it, turning the usual way this all works on its head.

Scott McCartney asked me to wax lyrical about some of the better mileage offers in the past, though I guess I forgot about dumpster diving for soda cups at Wendys.

Gary Leff, a co-founder of InsideFlyer, went to a hair treatment center offering 20,000 Delta miles for a consultation, even though he has a full head of hair. He and his wife went to a Jaguar dealer when Jaguar offered 10,000 British Airways miles for a test drive. They never drove—the dealership was happy to sign their test-drive form and not waste time and gas. On Christmas morning 2009, he used a stack of his own credit cards and friends’ credit cards to spend tens of thousands of dollars on an offer that netted 16 million US Airways miles for him and his friends.

I did manage to make the point that if a shopping portal isn’t going to honor the clear terms of an offer, they should be at a minimum providing some token compensation — like the AAdvantage shopping portal offer of 83,000 miles for a $60 phone where they gave 2500 apology miles and 2500 bonus miles for buying something else through the portal.

When merchants make mistakes, Mr. Leff thinks the honorable thing to do is to admit the mistake and offer a couple of thousand miles as an apology, not just cancel the whole promotion and say oops.

Ultimately it’s worth understanding how these shopping portals work.