Any time people are contacting you for a work at home offer, it's because they want to scam you. There are valid work at home jobs, but most involve little pay for a lot of effort. True telecommuting jobs that pay well usually involve a lot of specialized training in a particular field (and usually you aren't recruited while you are sitting on your ass at home watching TV or surfing the internet - not saying that you are doing these things, though).
By the way, please don't respond to any of these offers or click any links in the emails. 90% of the time they aren't even real offers for crappy jobs, they are used to harvest valid email accounts for spamming.