People are hungry for fuel-sippersAccording to the latest data for the months of January and February 2013, sales of hybrid cars are up an impressive 32% compared to the same months last year. So about 61,000 hybrids were sold in the first two months of 2012, and around 80,000 were sold in the first two months of this year. Still only around 3.6% (or 4%, according to other estimates) of the U.S. car market, but you have to start somewhere, and I wouldn't be surprised if future progress wasn't linear at all. Like many technologies - for examples computers and cellphones - it can take years to get a small foothold in the market, and then some tipping point is reached (because of price point, technological maturity, demand caused by external factors, etc) and progress becomes much faster.
Ideally, people should do most of their trips by walking, biking, or taking public transit, but if they are going to drive, they should use the most fuel-efficient and cleanest vehicle that meets their needs and budget. In many cases, hybrid models will fit the bill.