Actually i offered help to give info.. i know who this guys are i've worked with them once but some of your folks refuse so goodluck actually you guys would have a hard time shooting them down..
Same experience. Three times in 2 days. Each time, I didn't answer. When my own voice recording started to play, the callers hung up without leaving a message. No legitimate business would do that.
No. Scam calls like these are probably not to determine whether or not you're home. They come in from all over the country and sometimes from other countries, as well. Most are fishing expeditions trying to get your ID or credit card number. Some try to sell products with hidden costs and bogus contracts. One caller, for example, offers free installation of a safety alert device for the frail elderly and then charges huge sums for related "monthly service" that were not previously mentioned.
If you're on the Do-Not-Call list, it takes just a few seconds to file a complaint at http://www.google.com/#q=national+do+not+call+complaint. One complaint probably won't make a difference but hundreds might make the enforcers prioritize that violation.
And you probably already know not to answer. Any response on your part, including opting to be off their list, just makes the calls more frequent.