looks like steam accounts got new restrictions.

to get a full working account, you have to spend at least 5$.

"CD Keys, retail purchases, and gifts do not remove limited user restrictions."

Good. About time.

yes sounds right, but for example redeeming hb keys would not remove restrictions. you're forced to spend money directly on steam.

which is entirely correct, given how easy it is to get Humble keys

but it still looks like, there are opportunistic, greedy reasons responsible for this decision.

no, it looks like they have had enough of spammers and phishers.

They likely want to be certain that you are willing to spend money. A key from an external retailer (Humble, Gamersgate, Brick-and-mortar store, ...) and received Steam gifts cannot be (easily) traced back to you - any of those could be you scamming someone for a key (that doesn't quite explain the Steam wallet card though).

i don't meant the restriction idea by itself, just the decision to remove them only if you spend the money directly on steam

which is they only way for Valve to track and restrict.

(and see Maighstir above)

Keys outside of Steam can be got fraudulent, for next to no monies, or given/transferred from someone.

does anyone know, if the $5 differs in regions outside the usa?

Read your link. It is still $5, no matter the currency you use.

It's about time they implemented this feature.

The more they do to restrict phishers/spammers the better so I'm happy with this. Can't tell you how many hundreds of 'unassigned' and other assorted newly created accounts I've had to block over the years.

Personally I was hoping to get the ability to simply block people from sending me invites if their profile level isn't at least X (X defined by me, probably 10). If I want someone adding me I'm generally aware of that anyway so I can add them myself if needed or drop the restriction till it's done.