We will briefly discuss some reasons you may choose to buy silver products and these reasons may also influence what product you buy. This is a very brief overview and there are huge amounts of information available to better supports and discuss all these reasons and more.
Investing; Silver does have value and spot price fluctuates regularly. The prices often move inversely to the value of markets and currencies. There is also larger fluctuations in times of political and economic uncertainly. This can all get quite complex but for many people there is money to made in buying during the dips and selling at the peaks. Some people may try to make money speculating the collectors market on limited minted silver products, if they can buy at lower releases prices and try to resell on the secondary market.
Saving; Buying silver is a great way to induce savings for people who traditionally are not good at saving money. By buying a small amount regularly over time it can amount to be worth quite large amounts of money. People are more reluctant to sell their silver then they would spend their saving accounts.
Collecting; Many people are drawn to the artistic and collector value of the products. They like completing sets of various products. Many products are released annually and it has been very popular to complete a year set. Other mints also add "privy" marks or other details to there coins to add collector appeal.
Protecting Value; Silver or other metals can provide protection against inflation. For all those people who would advise stuffing your money in a mattress you must remember in 20 years that money would have far less value. If you invested that money in silver it would have the same purchasing power when it came time to use in years to come. If a period of hyperinflation occurs silver would have an exponential growth in value.
Doomsday; A lot of people buying silver are doing so to have something with intrinsic value if some global catastrophe occurs or a global financial crisis. Traditional currencies are backed by the governments that issue them and if for some reason there is a failure of the governments the currencies will lose their value. A lot of people to do feel this is inevitable with much of the debt crisis currently occurring. They feel silver will be used as a form of trade and barter once paper/fiat currency no longer has value.
Please feel free to add to the discussion in the comments below.