I went to Alexandra Palace yesterday, and as we sat at the top of the hill, overlooking the whole of London, we could see small groups of four or five people wandering around while holding their phones. It was obvious what they were doing; they were Pokémon Going.

I myself am a Pokémon Goer, but just casually. These guys (and they were all guys) were more serious. Each had a rucksack from which they would occasionally take out a bottle of water to sip from. From their phones were cables connected to external battery packs (GPS can really kill your battery). They’d come prepared.

There are those who are quick to dismiss this as a silly fad – grown adults wandering around catching imaginary monsters, but there is something quite charming about. Seeing people on the bus flicking Poké balls at Drowzees and Squirtles. Noticing strange little local landmarks at the nearest Pokéstop. The slightly sheepish nods of recognition exchanged between players. The parental bonding during walks in the park.

The success of the app inevitably brings up questions of how it can be monetized. This weekend, Nintendo’s share prices dropped by 17% after they issued a gentle reminder that they don’t actually make the app, following an irrationally exuberant increase in the last few months.

But beyond that, I’m sure every major brand is wondering how they can fold Pokémon Go into their marketing. Mobile phone power bank manufacturers are wondering how they can word their advertising so that customers connect the benefits of their products to the game (you can play Pokémon Go all day without your battery running out!) without explicitly saying anything that might get them into murky waters with Niantic’s legal department (‘You can catch monsters all day. Can we say “catch monsters”? “Catch monsters” is OK, right?”)

It will also be interesting to see if this filters down to the local level. With the summer holidays coming up, and if the weather stays like this, I wouldn’t be surprised to see ice cream vans parked on the sites of Pokémon Gyms, or shopkeepers using digital Incense to lure real world customers inside their stores.