Do multiple e-mail aliases on the same domain protect privacy?

Do multiple e-mail aliases on the same domain protect privacy?

Many web services require a valid email address for registration. If I use
the same address for every service, only one needs to be hacked, and soon
the adress is "contaminated" with spam. Furthermore, using the same email
address makes matching my behavior data across services dead easy.
The only solution to this I could come up with is to register some private
domain and then create aliases for every web service. Then, one can
identify which services have a spam leak. Also, cross site matching is a
little bit more difficult.
But I am completely unsure whether this works in practice. Will multiple
email aliases increase my privacy at all or do they simply shift data
matching to the (unique) domain level?
Is there a even better way to handle multiple web services without
ignoring the spam/matching problem?