The best athletes in the world don't just earn the best salaries.
The best athletes are able to maximize their incomes through endorsements.
In some special cases, the biggest sports stars of today are able to take home more money from their commercial deals than they do from their professions. LeBron James is a perfect example.
The perennial NBA All-Star brought in endorsement money that more than doubled his basketball salary.
Yup, companies love using athletes to boost their products, and apparently, they love using athletes' tweets, too.
Not only do sports stars make a lot of money by lending their images to certain brands, they also make an absurd amount of cash by lending those brands their thoughts in 140 characters or less!
Here are the athletes with the most valuable promotional tweets in the sports world:
Cristiano Ronaldo — $303,900 per tweet
Not only can Ronaldo pick up hot commodities off the market with ease, he can make any brand a hot commodity through his sheer social media-savvy force.
The Real Madrid star will endorse just about anything: underwear, suits, cleats, dress shoes, face exercise devices and even seemingly unnecessary sports apps.
Neymar — $143,000 per tweet
The 23-year-old Barcelona forward cashes in big with Nike.
Sure, the Brazilian has an array of secondary endorsements who helped chip in the $16 million he made from commercial deals last year, but it's his promotion of the ol' check that sticks out the most.
LeBron James — $126,600 per tweet
He's the highest-earning athlete when it comes to endorsements, with $53 million in 2014, but James comes in third on this list.
LeBron doesn't hand out promotional tweets often. So when he does, it sticks out like a sore thumb.
Wayne Rooney — $94,000 per tweet
The Manchester United and England captain, who took home $5 million in endorsements last year, is a generous tweeter. Yeah, he'll promote Nike, like most athletes, but you can also catch him retweeting local businesses in his hometown of Liverpool.
Kevin Durant — $80,000 per tweet
A bump in promotional power came with Kevin Durant's 2014 MVP Award.
The OKC Thunder star signed a new $300 million shoe deal with Nike in the summer and brought home $14 million in endorsements in 2014.
Those numbers are likely to jump, too, especially considering the value of his tweets and promotional posts, like this one:
Sergio Agüero — $63,000 per tweet
These days, the Manchester City striker spends most of his time on social media promoting his new autobiography.
But, that doesn't mean the Premier League's most prolific scorer doesn't have time to give a shout out to Puma.
Besides, he has to make that $5 million in annual endorsement money somehow.
Robin van Persie — $59,000 per tweet
The Manchester United striker, who might've scored the best World Cup goal you've ever seen, took a page out of a savvy entrepreneur's book.
The man they call RvP took his promotional tweets business venture (or whatever you want to call it) east.
This Chinese New Year tweet likely contributed to the $3 million in endorsements he already made last year.
Gareth Bale — $30,300 per tweet
When he's not being accused of being selfish -- essentially for not passing to Ronaldo enough -- Bale can be spotted promoting the Adidas' "There Will Be Haters" campaign. Just out of coincidence, ya know.
With commercial deals like this, it's no wonder the Welsh winger took home $11 million in endorsements last year.
Rafael Nadal — $26,000 per tweet
The "Spanish Armada" is the lone tennis star to make the list; his promotional tweets add to the $30 million in endorsements he made last year.
He seems pretty crafty with his promotional posts, too.
Which makes you wonder, was it really a coincidence he tagged a Costa Rican resort he visited during a recent family trip in both English and Spanish?
Hitting all demographics, huh Rafa?
Kobe Bryant — $22,300 per tweet
The Black Mamba might have trouble staying on the court, but, to quote Jalen Rose, he's gonna still "keep gettin' dem checks."
Still the highest-paid player in the NBA ($23.5 million), Kobe brought $32 million in endorsements, a total that was contributed to by tweets like this: