One can see it a bit like search where it can be more important to do fast exclude than to have correct include. Those 8 ad targeting groups are potential matches, but what the data do not say is the hundreds of targeting groups which twitter claim that you are not. This kind of fast classification is good as a performance/cost saving technique when the error cost is also low.

Also, one can be high spender and frugal. A person who buy one pair of very expensive shoes and wear them for 10 years rather than buying 10 pairs of inexpensive ones would be such person.