Edit: seems to have been there from 2009 till 2019 (!) after users took legal actions. See https://www.golem.de/news/t-online-navigationshilfe-telekom-... (german)
Redirecting you to an add page is terrible enough, ensuring that the ads on that page eventually served malware was the icing on the cake.
I imagine they're still doing it.
An angle no one has mentioned it how this played into googles dominance. These predators made it legitimately safer to type into a search box than a URL bar. At least for a little while.
They don't.
So yeah, preying on users who make frequent typos would also serve to target less observant users, who have the potential be exploited more easily than the general population. AKA: typos imply an exploitable weakness
Case in point: Verisign and Telekom squatting on typo'd domains to extract revenue from exploitable users.
Better use OpenDNS, etc just to have more diversity