I think it kind of fluctuates. It'll go up and then go back down. It doesn't just keep rising if that's a worry. I had sick kiddos at home yesterday, so I just let things run and did tasks all day and wracked up 271 points.
Be sure you're playing the games everyday- I play Swaggasaurus Run (I'm sure I butchered the spelling). You just let him fall off the cliff- don't bother with actually playing unless you need a brain break. Points and scores don't matter. You can get up to 10 SBs for that, and they give 2 SB about every other round. So just keep playing until you've got your 10.
Also watch the videos everyday. Today I reached my 10 SB cut off and it popped up saying "But you've qualified for a bonus!" So now it's rolling through 7 more videos to earn another 2 points. I've got the SBTV app on my iphone, and I just turn the sound off and let it run through the two 10 second Home and Garden videos over and over.
I did a dumb "Winter Trivia Quiz" yesterday that earned me 24 SB right away.
And I did Swag Offers: Hipmunk for 35. All you had to do was use it to search for a travel destination, enter the dates of your trip (it's like a travel reservation site) and let it search for hotels for you. You don't have to select one. That was credited within an hour of my search.