It’s becoming increasingly hard to gather leads because there are too many sources and potential buyers. For a human, it’s virtually impossible to acquire all of them, and the gathering process will be very slow. That’s the reason why you need web scraping.
If the proxy provider doesn’t have an ethical guideline to follow, you might expose yourself to a threat when using its proxies. That’s why you need to make sure that there are some rules your vendor obeys. Moreover, you should know what those rules have to look like to not let providers fool you.