Trading companies like baseball cards.

Jumia - the Nigerian founded online retailer that has aspirations to be the continental Amazon of the Nile - has settled on a three-forone trade - subsidiary for portfolio company - with Frontier Digital Ventures'.

The deal reads like this: Frontier will trade three online property classifieds portals from Jumia; Jumia to receive Afribaba in exchange - plus $500,000 in cash for its trouble.

Frontier is in the business of property portals (among other things) and their big wins have come from Australia and Asia. They will no doubt go on to merge traffic, listings, agents, etc. from these businesses with their existing portals meQasa in Ghana, ToLet in Nigeria and AngoCasa in Angola.

Property portals can be great businesses - at least we think so, we have four in our DCE fund across Asia and the Middle East - but in very informal markets, like some of those in Africa, there is no free koose-akara. Ask a Ghanaian for directions on the skirt of Accra and you are much more likely to get an estimated distance and cardinal bearing - properties often don't have a house number or name, and street signs are rarely visible if they exist at all.

The same goes for Jumia: how do you ramp up an online-retailing business in markets where users aren't online and have no address to deliver to? With difficulty one expects.

The billion-dollar question for one of Africa’s best-funded e-commerce start-up (at least for investors) is whether the opportunity afforded by Africa’s large and growing population outweighs the structural challenges the continent presents. Let's hope so.