Last weekend, well-heeled advertisers spent $5m for 30-second ads during Super Bowl 50.

With more than 110m viewers tuning in to watch one of the sporting world’s largest single events, the justification is clear: Super Bowl ads deliver reach few other televised events can.

But a super-expensive Super Bowl ad doesn’t guarantee advertisers the results they hope for.

Mortgage lender Quicken Loans learned that lesson the other day when its Super Bowl ad sparked jeers on social media.

The ad promoted the company’s Rocket Mortgage tool, which aims to simplify and speed up the process of applying for and obtaining a home loan.

But some viewers drew a parallel between the tool and the loose mortgage lending standards that caused the 2008 financial crisis, and took to social platforms like Twitter to criticize the company.

Quicken Loans responded quickly to dispel the concerns: Rocket Mortgage makes the mortgage process quicker and easier for consumers but the loans are still subject to stringent underwriting standards.

But even responding to negative buzz was turned into fodder for more negative buzz.

Clearly, Quicken Loans’ costly Super Bowl ad missed the mark with some consumers.

No company spending $5m on an ad during the Super Bowl would want to find itself in a situation where it’s having to defend itself publicly on a day when it should be basking in Super Bowl glory.

Traffic tells another story

Social buzz is just one part of the story, however, and negative sentiment can be deceptive.

Small minorities of vocal users can create a firestorm that appears larger than it really is.

With that in mind, Quicken Loans says that despite the criticism, its Super Bowl ad was a success. According to Jay Farner, the company’s CMO, the ad drove 14,000 people to the Rocket Mortgage site within the first minute its ad was broadcast.

“The win was driving folks to the site,” he told AdAge.

14,000 visitors in a minute does seem like a win, but is it?

Even if one assumes that Quicken Loan’s Super Bowl was responsible for driving 100 times that amount of traffic – 1.4m visits – it’s not clear just how big a win the ad really delivered.

While under this completely hypothetical scenario a cost of roughly $3.50 per visitor might compare very favorably to typical CPCs for mortgage search terms on Google AdWords, ultimately cost per acquisition is the metric that matters most and there are logical reasons to believe that Super Bowl ads probably don’t deliver high conversions.

After all, many visitors are likely visiting without strong intent.

Of course, most Super Bowl advertisers aren’t concerned solely with action. The Super Bowl is the quintessential branding exercise, so there are intangible considerations that can’t fully be quantified.

But even so, Quicken Loans’ experience demonstrates that despite their high costs, high-profile ad slots can still carry higher-than-anticipated risks and future Super Bowl advertisers will want to take those into consideration when crafting their ads.

And some might even find it wise to consider trying to capitalize on the event with lower risk, lower cost strategies.