Gumtree is a great place to advertise hyper-local (within your area) and local (within your peninsula or province), it is highly traffic and highly ranked in search engines and a basic advert is free. Gumtree does not do too well in national adverts (buyers from other provinces) as unlike bidorbuy it does not have a verified seller program or rating system and there has been reports of scammers using the site. Gumtree has in the last decade or so made certain statistics available such as age of account, whether poster has a verified Email and the amount of adverts the user has posted which helps establish trust. However there is no recourse if you are scammed.
I have sold province to province on a few occasions. Twice I had offered buyers in other provinces that I would list the item on my bidorbuy verified account which is over a decade on and has 100% positive ratings, the last time I shipped to Durban after sending the buyer by bank details without using bidorbuy. So it can be used as a lead generation tool in that way or to refer people to your website if you have one.
Gumtree is often referred to as a "community website" due to its roots, even though it was acquired by eBay in 2005. Gumtree started in London in 2000 as a way to connect people from Australia, New Zealand and South Africa moving to the UK find accommodation, employment and friends. This South African connection has made it the most popular online classifieds website in South Africa larger than even the Naspers backed and owned OLX.
Gumtree South Africa has changed its focus away from the friends' aspect in the last decade; it used to have Craigslist style "personal" ads for romantic partners and but has recently focused on the three most popular commercial ads: property, automotive and jobs (which are also popular with vertical classifieds).
However this roots is important to understand as Gumtree still has strict rules in place as to what is and what is not allowed on its website. Gumtree should thus be seen as a consumer-to-consumer portal also used by businesses. It has strict policies and a long list of what is not allowed: