@Laban,
The first sale concept appears to deal with copyright-able material such as books, movies and TV shows. The idea is when your 'purchase' a digital/or physical copyright-able material, certain restrictions as to how you can transfer ownership of that material apply. As far I know, there is no way to legally transfer purchased apps, musics, TV shows and movies purchase from Apple, Google or Amazon.
But for things like data bundles and airtime, the concept is to widely application, but also this appear to be a modern concept initially introduced by Safaricom with airtime transfer (they could have been the first, I don't know) and now Safaricom seems to be testing the waters and see how the market takes it.
Remember technology is way ahead of regulations, so industry leaders like Safaricom play a large role in how these things are eventually regulated. If consumers don;t raise their concerns, soon these kind of restrictions can become legal and enforceable by law.
So talk now or don;t complain letter when Safaricom quotes a legal clause when they finally put a expiry time on your M-PESA balance.
And I hope revisions to the ICT Bills deal with these things rather than focusing too much on those who 'misuse telecommunication equipment' laws used to deal with bloggers recently. But it appears the big Telcos have lobbying/financial muscles and the laws end up favoring them.