It was four days of insults, excess and expensive jet fuel. It also took the sporting world hostage with a barrage of front-page headlines that will go a long way in helping Floyd Mayweather and Conor McGregor approach their lofty box office and pay-per-view projections. 

Mayweather, the 40-year-old former pound-for-pound king, and McGregor wrapped up a four-city international press tour on Friday in London -- on the UFC lightweight champion's 29th birthday no less -- promoting their Aug. 26 boxing match in Las Vegas. 

The often bizarre spectacle was every bit as flashy and crude as one might expect considering the size of the personalities (and egos) involved. And, yes, at times it went too far. But it certainly left a huge mark, playing to one sold-out arena after another. 

As we count down the final 40 or so days until fight night, let's look back at what we did and didn't learn from the Mayweather-McGregor world tour.

What we learned

1. No other fighters could've pulled this off: Let's throw out this one disclaimer before moving forward: Four consecutive days of the same show proved not to be a good thing in the end, especially if you had devoured every second of interviews and trash talk. It's likely that two days would've sufficed, if not a radical change in format each day. But with that said, both Mayweather and McGregor performed the kind of improv, live comedy act (helped by a few pre-planned props) during the tour's top moments that  went a long way in making this, overall, a huge success. Whether it was Mayweather draping himself in the Irish flag and willingly playing the heel in front of hostile crowds or McGregor providing a witty one-up for nearly every comment Mayweather made, this was a top-shelf performance from both. 

Yes, it quickly became apparent that Mayweather failed to prepare four days worth of material. The tour also devolved at times into the areas of race, misogyny and homophobia -- items that sadly still linger within the fight game but make an incredibly poor advertisement to a mainstream audience in 2017. But both fighters flashed a sort of virtuoso ability in terms of marketing and performance that no one else could've pulled off with such apparent ease. 

2. McGregor really, really believes he can win: In the end, this might prove to be the best way to entice casual fans to purchase the fight: Place a microphone in front of McGregor, have him flash those crazy eyes and let him seduce you into believing he will knock Mayweather out. Admittedly, he's rather convincing in his attempts. McGregor has earned the self-given moniker of "Mystic Mac" in the UFC for how many times he has predicted the exact round and ending of his fights, despite the long odds against him at times. Everything he has claimed he would do throughout his MMA career, he has done. Hearing him break down, from a technical standpoint, why he thinks he can land punches against such a defensive wizard as Mayweather should've come across as ridiculous. But somehow and some way, it didn't. It's a testament to McGregor's outrageous confidence and his history of snake-charming opponents.

3. Mayweather was a salesman until the very end: There was an expectation from many that the press tour could prove more exciting and entertaining than the fight itself, which has been called a gross mismatch on paper. One of the big unknowns coming in centered upon whether McGregor could get inside the head of the always unflappable Mayweather, forcing him "off script" in terms of his mindset to produce an emotional and real reaction. Outside of some decently intense trash talk during the first few staredowns, that moment never really came. Mayweather certainly took his shots at McGregor during their comedic exchanges, from ripping his net worth in comparison to constant references to the Irishman's three submission losses in MMA. But he made sure to underwrite each of those statements during the backstage media scrums by putting over McGregor's chances at pulling the upset come fight night. With constant references to McGregor's advantages in reach and age, Floyd made sure the fight's bottom line was always at the forefront of his intentions. 

Mayweather can sell just about any opponent he faces in the fight game. USATSI

What we didn't learn 

1. How much the tour's crass negativity will affect sales: Devolving into one off-color and profane comment after another, the final two days of the tour seemed to slightly affect the overall narrative of the four days. The worlds of boxing and MMA are still largely insulated from the real world, which means athletes often make scandalous public comments when jawing with opponents that would get them fired in most professions, let alone team sports. For example, Tom Brady would be in a lot more hot water publicly than McGregor was for telling an African-American opponent to "dance for me, boy." 

Fight fans aren't as put off, for better or worse, knowing escalated tensions within combat sports and the "Wild West" mentality that prevails. But in order for this fight to eclipse the PPV buy record of 4.6 million set by Mayweather's 2015 victory over Manny Pacquiao, it will need to reach well past the fight audience. And in 2017, the kind of comments that were uttered by both simply aren't acceptable. The negativity didn't appear to hurt the amount of live stream viewers at home or sold-out arenas over the final two days but it's far too early to tell how much the profane turn for the worse will stop people from handing over $100 to help two of the richest athletes in combat sports laugh their way to the bank. 

2. How quickly we will see McGregor back in the Octagon … if at all: Certainly, there's an element of "wait and see how he performs first" before rushing to judgment on McGregor's next move. But most expect McGregor to lose handily against Mayweather, which opens up questions regarding his future. None of those questions, however, seemed to be answered convincingly by either McGregor or UFC president Dana White throughout the tour. White, no stranger to shifting gears unannounced in terms of the narrative he's painting, started the tour offering a certain element of doubt whether McGregor, following a life-changing payday, ever fights again. This, of course, contradicted his statements after the fight was announced that McGregor would return to UFC before the end of 2017. 

McGregor, meanwhile, stated his interest in continuing to chase big goals after Mayweather (reminding everyone he's only 29) but never provided a definite answer as to a timeline. The closest thing McGregor provided was his preference to continue fighting at lightweight, with title defenses against either Nate Diaz (in a trilogy) or unbeaten Khabib Nurmagomedov as his preferred choices. One thing White did make clear is that there wasn't any language in a contract between McGregor and UFC which states he must return to MMA in 2017 in order to accept the Mayweather fight. 

3. Whether Mayweather-McGregor will be the last of its kind: A boxing superfight between a top UFC star, let alone a champion still in his prime, and an elite counterpart in boxing was something we never thought we'd see. Outside of James Toney's embarrassing one-off inside the Octagon, UFC hasn't shown interest (famously banning Anderson Silva from facing a washed up Roy Jones Jr.). It's part of what made this fight so surprising to those who have followed both sports for years. But something very interesting has happened since this fight was first announced (when Dana White shot down the idea that more crossovers would come) and last week's press tour, when he showed up at two of the stops curiously wearing a "Zuffa Boxing" t-shirt. Zuffa, of course, was UFC's former parent company (owned by Lorenzo and Frank Fertitta) until last summer's 4 billion sale to WME-IMG. White remains best friends with the brothers.  

Some have rumored that Lorenzo Fertitta, still a trusted adviser and confidant to McGregor, played a sizable role in his former company stepping out of the way for McGregor to pursue the fight. Under that line of thinking, White's choice of t-shirt may have been a calculated statement regarding his future intentions. Remember, it was White and the Fertittas, a trio of frustrated boxing fans, who teamed up to purchase a UFC brand which had almost zero presence on television and had issues getting regulated. Together, they built a promotion that was purposely implementing the kind of marketing strategies and must-see matchmaking that boxing was no longer doing. Last year's UFC sale made both the Fertittas and White filthy rich (with White staying on in his role as company president and public figurehead). 

Could a future in boxing promotion, including more crossover fights like Mayweather-McGregor, be the next step for White and company? He was noncommittal when asked. "You never know … you never know," White said, flashing just enough of a sly smile that screamed he has something fairly substantial up his sleeve.