When Donald Trump announced his presidential run last year, many brand experts called it a giant marketing campaign aimed more at his boosting his businesses than winning the White House.

But now, Trump's campaign troubles could be spilling over into Trump Inc.

Even before the political controversies of the past week, some of Trump's hotels, golf courses and properties were showing signs of pressure.

According to Foursquare, the share of traffic going to Trump-branded hotels and golf courses fell 17 percent in June and 14 percent in July. A separate analysis by Hipmunk found that bookings to Trump hotels fell more than 50 percent in the first half of the year.

Granted, the outside estimates are only a partial snapshot. The Trump Organization — Trump's umbrella company — is privately held and doesn't disclose sales or traffic at its properties. In his financial filing to the Federal Election Commission in May, Trump said revenues at his various businesses were up $190 million, to $557 million, over the previous year.

Revenues from the Trump National Doral Miami, for instance, more than doubled to $132 million, from $50 million a year earlier, the filing says. Revenues at Mar-a-Lago, his Palm Beach resort, nearly doubled to $30 million. His branded businesses and book sales also surged.

But these numbers are Trump's numbers — and they don't capture the more recent stage of the presidential race, when his brand has come under fire. Since a tape was released last week showing the nominee making lewd comments about women, his so-called brand strength has deteriorated, according to Brand Keys.

A spokesperson for the Trump Organization did not respond to CNBC's requests for comment. But a rally in Florida Thursday, the candidate denied new allegations that he had inappropriately touched women.

One area that hasn't shown weakness, at least yet, is residential real estate. Anti-Trump TV personality Keith Olbermann touched off a wave of media speculation this summer, when he Tweeted that he sold his apartment in a Manhattan Trump building for a loss.

"Now that I've escaped, I can report to you that the market in NYC @RealDonaldTrump apartments is in free fall," he said.

Yet the data suggests otherwise.