As a person who has interviewed and hired for technical job roles I can honestly say this does not make a difference to your chances of being hired, I do however agree with jcmeloni in that being polite is "never lame or unnecessary".
If we keep things as simple as possible, you will get hired because:
- They think you can do the work
- They think will get along with the others (in business speak you "fit")
They will also take into account risk factors for hiring you, including (simplifying again):
- How long they think you will stay
- If they think you have skill gaps, how long will it take to teach you what you need to know (and can you be taught what is needed)
Being polite via a follow up email has never swayed me into choosing a candidate over another, however, it won't hurt your chances either.
What I think would be a good cause for a follow up email is researching an answer you didn't know the answer to during the interview, and then contacting the interviewer with a solution and asking if you are on the right track. This will show:
- a willingness to learn
- a willingness to attempt to solve problems (shows you don't need someone to 'babysit' you)
- and a willingness to seek guidance when you are new to a particular subject
These are all good qualities for someone in a technical role, as it is a very rare that a single person will know all that is needed to know to determine a technical solution. An email of this kind would make me remember you and discuss what you had done with others, and will influence directly hiring point #2 and risk point #2, above, and to a lesser extent, hiring point #1.