If you’ve received positive feedback each time you’ve talked to the hiring manager, or are asked to keep them apprised of your job search progress, you have the green light to maintain the lines of communication open until told otherwise, e.g., We will get in touch with you, or get no response. You might send links to interesting articles; let the hiring manager know of a relevant industry webcast or seminar; keep them apprised of any kudos you’ve received at your current job; a charitable project you just completed, and so on.
Here’s exactly how many times you should follow up after a job interview