they are sharing your most personal financial information with lenders and creditors; best of both worlds for them... Skin you once, flip you over, skin you again.
First, which most personal financial information are they sharing? They're only privy to credit reports now, no? A lot of these lenders could do their own soft inquiries and get the same data for a tiny fee.
Second, I'm not sure they need to share anything as they're facilitating conversions directly by evaluating your information and then suggesting the most likely convertible products (cards, loans). There's no need for a service like CreditKarma to explicitly hand that data over.
I don't know what "need" means in this context. That is what they do - sell your data. Perhaps a different company that didn't do that could exist, and in a different sense, CK doesn't "need" to do anything, even exist. But they do exist, and do sell your data.
"Need" means they make money without selling data directly (as described above). In fact, they probably do/would make more money through direct conversions than data sales when the data is generally available anyway.
In other words, they have access to data that is available to anyone who can make a soft inquiry. That's a lot of people. It's easy and cheap.
