Why are Parent/Sibling DNA Comparisons so Confusing?

We each inherit 50% of our autosomal DNA from our parents and we also share around 50% with full siblings yet the number of centiMorgans (cMs) displayed for full sibling relationships on the majority of testing sites is substantially lower in comparison to the amount displayed for parent/child relationships - the big question is why the anomaly?  If you have ever been perplexed by this inconsistency then tune in to this TechZone video as Michelle explains all and clears up the confusion.