It’s been just over year since a slew of rapid grocers – promising delivery to the door within 15 minutes of ordering – began operations in earnest in the UK.

The business model is straightforward enough. Establish dark stores stocked with a range of around 2,000 SKUs in locations with high population density. Recruit pickers to pack orders made via an app, with a fleet of couriers primed to deliver those orders in a flash. Spend big on marketing to reach high volumes, and mark-up products by enough to cover all those not-insignificant costs.

Profit? Not yet. At best, a few of the rapid grocers say they have a handful of dark stores that are profitable. The unit economics are sound, others say, and it’s aggressive growth keeping them in the red. Nazim Salur, founder of Getir, recently compared his cash-hungry business to an aeroplane. When “just taking off, it consumes a lot of gas” he told the Wall Street Journal.

While that’s a fair point – see Uber, Deliveroo et al – others remain sceptical the business model as it looks now will ever make money. Now, with investors possibly growing tired of the seemingly endless cash withdrawals, there are signs the sector is starting to scrabble around for alternative revenue streams.

A sound strategy? Or an admission the model makes little business sense?

The Grocer revealed yesterday that Getir is to trial customer click & collect from several of its dark stores. It’s something that’s also being pursued by Jiffy from a couple of locations in London. Meanwhile Gopuff – in the US at least – is opening mixed-use sites where customers can enter and order products on a digital kiosk which are put together behind the scenes. The sites also function as delivery dark stores.

Several retail pundits pointed out this model seemed familiar. As analyst Natalie Berg put it: “Also known as… convenience stores?”

A boost in volumes from those happy to walk certainly makes sense – think of the savings on rider labour – but it does rather call into question rapid’s raison d’etre: that consumers want products to their door, and immediately. It’s yet to be seen whether pedestrian dark store purchases are incremental or not.

Trying out click & collect to unlock revenue at existing sites is one thing. But other rapid players have indicated more fundamental business model moves.

Late last month Jiffy launched ‘Jiffy Q-Commerce as a Service’. The service – which has secured a big-name first customer in BrewDog – enables brands and retailers to offer sub-15 minute delivery of their products, via their own DTC site, but using Jiffy’s ordering system and fulfilment network.

In other words, Jiffy is turning from retailer to more like an ultra-rapid THG. It’s a bold move. Giving up the customer relationship, swapping margin for commission and missing out on upselling and app-usage.

Yango Deli hinted at a future even further behind the scenes. The company – which only launched in the UK in October – is already “exploring the opportunity” of offering its proprietary technology to retailers.

It comes from the company’s forecast that ultra-fast delivery will become an expectation of consumers in coming years. “In five years when this model is considered a major threat to traditional retail, retailers will be investing to be in this market themselves. There would be demand,” said Yango head of international markets Maxim Avtukhov.

Given Yango’s tech background – it’s owned by multinational internet giant Yandex, often called ‘the Russian Google’ – this isn’t so strange an ambition. Avtukhov likened it to being like Ocado is for many grocers around the world (but for rapid).

Businesses should always be looking to diversify and innovate. Nobody finds it strange, for instance, that a supermarket with physical stores also sells online and has a clothing range. But coming out with such big changes to the core proposition so soon after launching could signal to some that the rapid grocers are having a crisis of faith. Is their current model really all that’s required to have a profitable future?