Anything's possible... likely? No, it will take you millions of years to find a block on average. As for why they sell them to you, it's because it's easy to sell hardware to people who don't know what it is they're buying if the sales pitch is all bullshit.
I bought on Amazon UK, And sales pitch was that I could earn at least 25 bitcoin per month. If that's really not true I will raise an issue with Amazon
That is the biggest load of horse shit I've heard in a very long time. You won't earn 25 bitcoin from them if they mine for the next 100 years.