Okay, I could be totally wrong as I'm still pretty new to the SPT game myself but here's my shot at getting voting power.

As you might notice you get SPT for posting and getting upvotes. Then you notice that my upvote gave you 0.13SPT. I know, pretty sad but still better than zero.

How did I get that SPT voting power? Well, when I got paid my SPT I went to my wallet and staked it into SPT power. Now my 650 or so SPT being staked lets me share the love at least a little bit when I click the like button.

Hope that's helpful.