As I mentioned in the gaming post, potions haven't been updated since the second book. This is especially peculiar as after little over two years (Three counting Beta), Pottermore is on it's fourth book. This makes it seem that potions will continue to suffer, though it's the weakest method of earning points on the site thus far, though I will discuss a few ways that this could be fixed, and mention a bit of what is rumored for the future.
To recap, there are currently 9 separate types of potions (8 if we call the two parts of Pollyjuice one potion). However, only 7 of the 9 give points, debatably because Pollyjuice is "against the rules". Because of this and the time limitations that are inherent in potions, and the cost of brewing (being at the least 15 Galleons for the cheapest cauldron), potions serve as a much weaker alternative to Dueling as a point earning method, though debatably potions is far more reliable. Potions also occasionally have had effects in the game, not unlike spells which can be cast at certain moments. However, as of the "new" Pottermore switching to become comparable with HTML 5, moments are able to be skipped about. Now in the first instance of Potions being a "unlocking" event, the completion (or acquisition) of a certain potion allowed a user to progress in the story, and in the second instance, this allowed more levels of interaction with the moment itself. These are the potions introduced in Chamber of Secrets, the Swelling Solution and Pollyjuice Potion.*
First of these would be Swelling Solution, which is oddly enough my favorite choice in designing pottermore (though it was ruined by the new update). Now as I've mentioned, there is not much of a motive for many individuals to attempt brewing. Not only is there a chance of losing points, but unlike dueling, it's limited by galleons, and takes up a set amount of time, with a fairly minuscule compensation when compared to a successful duelist. However, this Swelling Solution initially prevented progress unless someone somehow obtained it. This meant that individuals would have to either a) brew it or b) rely on friends to brew it and send it over. The benefits here are twofold. It encourages people to brew, and/or encourages individuals to make friends and exchange items on Pottermore, forcing an aspect of interactivity on users. You can't brew it? Too bad, make friends, I'm sure they can. An expert brewer? Wow! You know you can make things for people, and if they can't make it, you can just ask for the materials. This effectively created a very, very basic market on Pottermore and this is something that has been around since Beta when Galleons were scarce and potions were the only way to earn points. As a result, users bonded over the difficulty, and there was a greater sense of camaraderie than the dueling focused house cup that Pottermore currently has.
Now how do we make this happen again you may ask? Well this brings me to the current roles of Swelling Solution and Pollyjuice Potion. Both potions "unlock" more interaction with moments.** If Pottermore were to ever hide a new spell book***, it could be obtainable ONLY after an individual completes or obtains a certain potion, and this would force camaraderie once again. Users would be trading ingredients for a bigger point earn in the long run and brewers would be in a spot where they are once again viewed as a necessary partner to the dueling overlords.
I am not quite certain if this will happen in the near future. As of my time writing this, I am aware of two potions to be added to Pottermore sometime in the near future, being love potion and the draught of living death. **** While this is to be taken positively, the fact that love potion in particular is not brewed till the sixth book does draw some concerns, and implies that the potions mini-game on Pottermore may indeed be a "unwanted stepchild" from now to the very distant future, though that can always change with the release of new cauldron mechanics and such to either shorten brewing times further or make certain potions "auto-completing" eliminating the second stage of steps. This "smaller" fix could help Potions pick up the power that it lacks compared to sheer dueling, especially if it's combined with point increases or partial points for completing the first part of a potion.
*Again... Polyjuice potion has 2 parts.
**Technically Swelling did two roles: Block progress AND open a cabinet to snape's storage closet. the moment was changed though the rewards are the same, giving the first brewing of swelling a 9 point value (7+2 points from collecting ingredients
***This would be a spell book with actual new spells that can be used in dueling, and overshoot the current "cap", say allowing a spell with a 160 maximum with a 150 average as opposed to the 140s range that Body bind is now
**** Both potions can be found if digging is done about Pottermore's source codes, along with a few spells, and one badge. All of which seem to be fairly useless unless they are actually going to be placed into the game.