Why am I getting flooded with calls from recruiters?

Back in the beginning of 2007 I was in the market for a new job. I worked with a lot of recruiters and was able to find a new job fairly quickly. I continued to receive calls from recruiters until about 2008 when the job market really went into the tank (luckily my current job has sustained since 2007). About 2008 calls from recruiters just stopped and I have not received any calls since then. I'm assuming this is due to the conditions of the job market. However, this year I am all of the sudden being flooded by calls from recruiters to see if I am looking for work. Started maybe 4 months ago. Could this be an indication that the job market is picking up? Are others getting calls as well?