New signings bring excitement for fans, hope for clubs and new opportunities for players. But in 2017, it's also what they bring off the pitch that can make a huge difference, as two recent Bundesliga moves show.
Chicharito's departure from a Bayer Leverkusen side attempting to rebuild yet again isn't a surprise, but it is a transfer that highlights of a new age of numbers in football.
Data collection and analytics is a growing obsession, but it's the off-the-field numbers that carry a rapidly increasing weight for clubs. Clearly, the player has to be able to contribute on the field but the off-field effect is not to be underestimated.
Aside from his goals, Chicharito, who will move to Premier League side West Ham United, takes with him an army of supporters (eight million on Twitter) and a bank vault of shirt sales. It's tempting to believe Leverkusen will be concerned only with the former, but there's no doubting the importance of the 108,000 followers (down from 111,000 two days after Chicharito's transfer was announced) of Bayer Leverkusen's Spanish account - and it's clear who most of them were there for. The number of retweets and likes for the Mexican's departure tweet alone further demonstrates his importance to Leverkusen's standing in the Spanish speaking world.
Even if his form dried up towards the end of his stint in Germany, his presence in the shirt was invaluable for both Leverkusen and the Bundesliga. The striker's popularity was so high that, at one point, he had a section of the Bundesliga website dedicated solely to him.
A few years ago, the league itself might have seriously feared the departure of Chicharito for exactly those reasons. Now though, thanks largely to a busy Bavarian summer, his departure will make much less of a dent on those all important numbers.
The arrival of James Rodriguez at Bayern Munich makes Hernandez's marketing figures at Leverkusen look solid but unspectacular. Marco Fabian will carry the Mexican flag in Germany, but now it's the South American market that offers the most promise for the Bundesliga.
Arturo Vidal, perhaps the last big name from the continent to arrive in the Bundesliga, packs a punch on the field, but his numbers look positively tame when stacked next to Rodriguez's.
Vidal's on-field bite is matched with social strength - he has 3.2 million followers on Twitter - but Rodriguez is on another level. The Colombian has nearly 13 million on Twitter and on Facebook he has an astounding 32 million (the population of Colombia is 48.6 million) fans.
The marketing power of top players is astounding and Rodriguez's move opens the South American market to the Bundesliga like never before. Back in the glory days of Ailton and a younger Claudio Pizarro, or in the even earlier days of Jorginho and Lucio, players didn't arrive with an army of online supporters. They played games, scored goals and sold shirts.
But just as the game has come on since then, so have the factors surrounding a transfer. The fact that a South American legend like Bayern's Brazilian striker Giovane Elber has returned to the club in a promotional role is a reminder of how big the game has got and how different it was even 15 years ago.
Bayern Munich, Borussia Dortmund and Schalke enjoyed preseasons in China, Eintracht Frankfurt were in the US - but unlike tours of the past, those in 2017 are an extension of the work being done week in, week out. Although late arrivals to the international marketing game, it is clear Bundesliga clubs, and the league itself, are quickly pulling a shirt on and looking for a follow from every football fan on the planet.