For the purposes of jurisdiction, Eventbrite will be an ISSP under the EqA (Information Society Services Provider). There are specific exceptions carved out in the EqAct in relation to ISSPs in EU countries, where the equality legislation of the relevant EU country will prevail.
Other than that, the EqA is deliberately silent as to its territorial scope and it comes down to facts. Would a High Court determination really find against Spero in the circumstances? As I said above, Eventbrite uses of a co.uk website to advertise both its own services to organisers and the organisers' events themselves; events held in the UK and attended by UK consumers who purchase tickets through Eventbrite via links from the UK site. You need to log in and register to a UK site to buy tickets or create an event. They even offer tailored advice to UK organisers for maximising their ticket sales in the UK using stats about UK ticket buyers:
www.eventbrite.co.uk/blog/when-do-people-buy-event-tickets-ds00/
This all screams services being provided within our jurisdiction. For Eventbrite to argue otherwise is not a good look for them and their business model - why would UK consumers or organisers risk using them, if they claim that statutory tort provisions like the EqA that protect our citizens do not apply to them when they are in the business of asking our citizens to use their Services via their UK platform? How will that go down as a publicity/marketing strategy?
Regarding the EU triggering provision in the case of a User who is not using the Eventbrite Services to further their trade, craft, business or profession (TCBP), I would say there’s room for an arguable case in favour of Spero.
Some Organisers are on the site to sell something they provide as a business e.g., a spa day. The contract between Organiser (e.g. a Hotel & Spa business) and Consumer is for a product that that the Organiser creates - the purchased ticket/voucher gets the Consumer the Spa experience. That’s a fairly straightforward case of the Organiser using the Services to further their TCBP..
Let’s say for the sake of being Devil’s advocate that Spero is in the business of selling a book. Spero is using the Eventbrite Services only to sell tickets to an event. She is not using the Services to sell books or a voucher that can be exchanged for a book. The Consumer buys a ticket to the event. That ticket gets them access to an event, it doesn’t give them Spero’s book. Spero’s side of the contract is to provide an event fulfilling its advertised description. She is not an event organiser by trade or profession, the event itself is not her business or her craft. Ticket purchasers get what they paid for by turning up to the event to hear Spero speak. Turning up to an event to hear Spero speak is all the ticket purchasers paid for. In speaking, Spero is not engaging in a business as she is not a professional speaker being paid to speak. Once the event is over, that’s the end of the contractual relationship between Spero and the ticket holder that was serviced through Eventbrite Services. If one of the ticket holders attending then goes on to buy a book from Spero, either at the event venue or from elsewhere, that’s a completely separate transaction that has not been serviced through Eventbrite Services.