Another tip you can use is just reach out to the prior agency and say something like the following: “We realise you were using link networks for our website which has resulted in a Google penalty and loss in business. Can you please remove my website from any link network you have built?”. If the prior agency is decent, they will remove the links from the network.
Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
What does that mean for you? It means Nielsen will pay you $50 a year to keep their app on your favorite internet browsing device. The app itself collects statistics on your internet usage anonymously, so you never have to worry about any data being linked to you. And the best part is, the app takes up barely any space and doesn’t slow down your phone or tablet at all!