I use Privacy on a rare basis. It doesn’t require a browser plugin, you can just log into their site and copy/paste the information.
It is worth it for me as I use it to sign up for “free” trials that require credit cards and then I don’t have to worry about getting charged.
A note about credit cards, if you have a history of payments with a company, that company can ask the issuer for an updated number after you get a new card number. If it works then they just store the updated number and keep up the subscription.
What service do you use? Been thinking about doing the same sort of thing.