"We do not allow our third-party service providers to use your Personal Information for their own purposes and only permit them to process your Personal Information for specified purposes and in accordance with our instructions, unless the data is rendered fully anonymous."

You didn't quote this part.

To me, the most straightforward reading is that Ditto does their own advertising, and targets it to specific users by using third party advertisers (Ditto paying the advertisers to place an ad, not the advertisers paying Ditto for the information), who are contractually bound to only use that information to deliver the ad that Ditto placed and not to use the information for their own future benefit.

The only possible reading I can see where this can be interpreted as selling personal information is the fact that the "Advertising and marketing partners" bullet doesn't use the phrase "service providers", and that thus, the contractual restriction on "service providers" could thereby exempt that bullet. Is this what you are hanging your interpretation on?

(Reason for my interest: I regularly read privacy policies, looking for loopholes; there's a huge range not just in privacy practices but in how clearly they are described. Ditto's could be clearer - perhaps by including an explicit statement that they don't sell personal information, as some do - but Ditto's privacy policy is not what that of a company who sells personal information as part of their business model looks like.)