Do you need it?
The short answer is no. You are never required to buy service protections or extended warranties. With this said, certain situations should force you to consider buying it. Pricey electronics, a second hand, refurbished tablet, or an after market smart phone, are all items you should consider getting protection on. Due to the nature of these items, even if all internal configurations are replaced and brand new, something can go wrong. When you buy second hand, you are buying "as is." So, if you don't have the second hand buyer protection, you just threw your money away. For these pricier items, and electronics, consider making the investment.
Should you buy it?
Again, this is a question each individual will make, based on purchases being made. If you are buying a second hand pair of shoes, which are marked at 95% off retail, are you really going to invest in protection for this item? It isn't the wisest move. But, electronics, second hand garden tools, power tools, and other pricey refurbished items, should be protected. Not only does it cover you from potential damage, it also ensures you are covered, if you need to send the item back for service.
Like any warranty or extended protection you buy, second hand buyer protection is optional in nearly every case you buy second hand. However, for certain purchases, it is a good idea to invest in, rather than take a chance and hope things work out, if you want to ensure you are covered in the event of damage, failure, or the product simply not working as it was promised to you.