Sony has announced that this weekend will be allow all PS4 owners to access multiplayer options regardless of a Plus membership. The free weekend for non Plus members will run from 6am GMT on Friday the 13th, until 6am Monday 16th of February. This weekend won’t let non Plus members access the monthly games, and Plus discounts on the store or the cloud storage feature.
Of course this is a promo offer to boost Plus subscriptions but instead of just having free multiplayer Sony should have made the Plus games availiable too, just as an extra sweetener for the weekend. Not everyone who has a Plus account does so just for multiplayer, and showing non-members an example of games they could be getting as part of the membership could make them more interested.
A few months ago Sony confirmed that Plus membership numbers had reached 7.9 million across its consoles.
Source: PS Blog