If you have one or two very strong certifications, like CCIE, they'll help you. Not much, far less than a degree, but they're a positive factor. I'm not every employer, but I'll never turn someone away for lack of a technical certification.
On the other hand, if you have 10 weak certifications (CCNA, MCSE, A+, Security+, etc.) and you list them all, that's a big negative. Huge.
Employers/hiring manager/HR are all different in their methods and perceptions. I was hired for one of the best Corporate Tech gigs I've ever had in first interviews wearing jeans with holes ripped in the knee that were big enough for a plate. I've also been turned away from a tech job because I had a top button in a dress shirt undone once; These are superficial things. If there isn't any glaring issue in a Resume that shows a lack of time and review, I'm more likely to turn people away for objectionable content on their Facebook account than I am because of the lack/addition or structure of resume content.
With ~30,000 CCIE's out there, I think most employers with any form of large scale networking would take notice at seeing such a listing on a resume. When I see someone who has a CCNA I'm comfortable believing that whether they remember a trivial line for IP SSH Authentication retries off the top of their head or not, that within 2 weeks of being in the work environment they will have refreshed their memory on the things they've already been familiar with. They might not know anything about BGP besides its name, but they have a framework for future learning and can adapt since its obvious they have at least a base understanding of using the CLI.
Doers do. They rarely bother with certifications and even if they do they have far more important things to tell me to sacrifice the space on their resume to such trivia.
This probably has more to do with the fact that they're already comfortably employed. Nobody wants to go spend money and time on a cert that expires every few years if they're not likely to see a pay increase for doing what they normally do; This especially applies to people who are able to transition to new positions without a cert because they are reasonably able to demonstrate to a coworker/superior that they can XXXXX. I have expired certifications for various things that I will never renew, but their expiration hasn't stopped me from listing them when I've needed work in the past. Just like any other degree or cert, they're a sign that I can play the game while also giving someone a further impression of past experience.
Interviews that solely parallel proselytization by a religious fundamentalist with every obscure question and answer from their point of view covered are often a waste of time.
Promising costs nothing, it's the delivering that kills you.