Besides, is going on the black market illegal?
Because tax evasion or participation in a black market activity is illegal, participants will attempt to hide their behavior from the government or regulatory authority. Common motives for operating in black markets are to trade contraband, avoid taxes and regulations, or skirt price controls or rationing.
Likewise, why do black markets exist? A Black market is a sector of the economy where transactions occur without the knowledge of the government and usually involve the breaking of certain laws such as filing proper tax returns. For example, if price controls or quotas exist for a good, then usually a black market develops.
Keeping this in view, what do they sell on the black market?
The usual fare sold on the black market consists of the expected bank account credentials, credit card numbers, full identity packets for $40, and DDoS and spamming services.
Is the black market good for the economy?
Just because the black market is full of illegal goods and transactions, doesn't mean it operates in isolation. Money goes in and out of the black market, so it does impact the real economy. Depending on the goods and services, the black market can also impact supply and demand for an individual firm.