Media PR Tip #3 - Not all things are newsworthy
Some people do press releases at the drop of a hat, thinking "The More, the Merrier."
A few PR firms try to take a good customer case study and sell it as a press release. "Look what our client's customer did with TA-DA!" Or try to turn their hiring by a company into a press release when really it's just another form of advertising for the PR agency -- paid for by the customer.
In the other camp, you have people who are so apathetic to do press releases, they don't send them out on a regular basis and then complain that they never get written up.
Good newsworthy things are things like--
You may not want to over-do press releases. If you are a small to medium-sized company, a couple of press releases a month on average isn't bad, with maybe 3 to 5 press releases during the course of a major trade show. One particular small company in the VoIP space never shipped product sent out a flurry of press releases during a trade show; about 7 or 8 over a two to three day period before reporters started deleting them as they got them.
You don't have to send out a press release every time you have a minor revision to your product (but, sigh, sometimes you do anyway).
This may sound contrarian, but when in doubt but you think you have something a bit meaty, send out a press release. It could be a slow news week and it might get picked up by a reporter.
Summary
You don't have to send out a press release EVERY week.
Averaging a couple of press releases a month is good with a "flurry" of 3-5 announcements during a major trade show.
Some things aren't really newsworthy. Like, who your PR and marketing firms are.
When in doubt, if you have something a bit "meaty," send out a press release.