By itself, it doesn't mean much. But as one attorney put it, think of it as another brick that, with all the other bricks, builds a structure. Circumstantial evidence can be just as damning as, say, a videotape of the actual murder, if put together skillfully.
"...think of it as another brick that, with all the other bricks, builds a structure."
Or they can just as easily remain a 'pile of bricks' due to lack of mortar. My take is that the prosecution is building his house from either straw or sticks, not bricks. When the 'big bad wolf' (Geragos) comes by he will have a good chance of blowing down the house built by the prosecution.
Even though I believe him to be guilty, I can see where a reasonable person could argue that he is not. Like it or not, that is the litmus test. Right now I would have to vote not guilty.