Sometimes more points sometimes less?

Try reading the FAQ.

its based on gifts not time. so the more things there are to enter the more points to do it with. the fewer added the slower regen.

point generation is 5% the value of new gifts added

(The way steamgfits does is better than a steady regen. a well balanced time based system has point starvation in times when there are many giveaways and such a surplus when there are fewer gifts people enter for things they don't want just to stay below the cap(300). this giveaway based one is more a constant proportion.)

...

Every 5 seconds, a d120 is rolled by a monkey. If the roll is 120, we get a point.