Different point of view on the details already provided by @unboiled, @TheBTCManual, and @Uppercase_DANIEL:

We have a steadily growing number of merchants accepting Bitcoin Lightning payments directly. Probably not more than 1000 across the country. These merchants are concentrated in the Western Cape province, especially around the Garden Route district. In the small, quaint town of Witsand, there is a strong culture of accepting Bitcoin, making it possible to live on Bitcoin (almost) exclusively. Another small town, Plettenberg Bay, has more than 120 merchants accepting Lightning payments directly.

MoneyBadger, a locally developed LN-to-fiat, QR code based payment bridge, allows users to pay any supported payment QR code via their preferred Lightning wallet. Check out their Xitter for videos on how it works.

One of these supported QR code payment providers, that has integrated MoneyBadger, is Scan to Pay. The 650k+ number originated from their blog post announcing the integration. Apparently the number is a slight exaggeration: it refers to number of payment points. That is, if a large retailer has 10 payment points at a site, that counts as 10 "merchant locations". The number of individual sites is apparently closer to 100k. It's still a massing accomplishment, making life a lot easier for those of us trying to live on sats.

It's important to note that all of these "650k" locations have this LN-bridge enabled by default. Merchants do not need to opt in. From their point of view, nothing has changed. Their invoices are still settled in our local fiat shitcoin.

Another important, and widely used QR code payment provider is Zapper. Merchants also do not need to opt into MoneyBadger, but it appears as if general usage of Zapper is declining, based on the fact that many individual branches of Zapper-enabled franchised has Zapper disabled.

The impact of these two integrations is huge! It enables anyone to pay for anything from fuel, to groceries, clothing to restaurants, cabs to local flights, all in sats.

Peach Payments is an online payments provider with MoneyBadger integrated. This one is different, in that merchants need to opt into accept "crypto payments" for it to be available.

Pick n Pay is a huge local retailer, and the first to integrate MoneyBadger in 2021/2022, when the app was still called CryptoQR. What makes this more interesting is that one can pay things like municipal accounts at Pick n Pay terminals. This is how, with MoneyBadger and via Pick n Pay, South Africans can now pay their municipal accounts with sats!