A small investment in these stocks now could lead to heaps of dividend income by the time you retire. Would you like to improve your passive income stream but don't have a lot of extra cash to throw around? If so, I have great news: These days, $100 is all it takes to acquire a share of three top dividend-paying stocks. Pfizer (PFE -0.73%), Hercules Capital (HTGC 1.14%), and Verizon Communications (VZ 0.57%) offer an average yield of about 7.6% at recent prices. They might not have the fastest-growing payou ...