This is a tricky question, because it's very difficult for a consultant or PR firm to get major press like this for a startup unless the startup has an amazing, innovative product, is doing something so incredible that it has to be talked about, or has a fantastic story behind it.
A PR firm is only as good as its clients' stories, and they often can't get the press the client wants.
There are strategies for getting into the press on your own without spending a fortune on a PR firm that may or may not be able to get the tech press you want. As well, there are things that a consultant can do to help you build the narrative to make your startup as appealing as possible to get into the national tech press.
We've gotten major national press (Inc., USA Today, Fast Company, Technorati, MSN, Yahoo, Intuit, Tech Cocktail, etc.) for ourselves and our clients. I'd be happy to talk with you about what we can do to help.
One of my former startups was covered in many publications (Techcrunch, USA Today, NY Timers, Venturebeat, etc.). We used multiple consultants and PR firms with varying results. I've found that if you have something very newsworthy like a product launch, consultants can use their relationships to amplify your coverage. Especially if the consultant/firm specializes in your industry.
However, I think of hired PR more as an amplifier. If you don't have newsworthy stories, it's hard for them to generate great press. The companies themselves typically need to generate these ideas, which can be a lot of work. It can be a lot of fun too, but you have to make sure it's a good use of time and focus versus everything else you could be doing.
I normally try to brainstorm along various categories of stories: product/feature launches, interesting stories based on data (OK Cupid and Pricenomics are great at this), customer success stories, guest posts by the founder, etc.
Finally, I think many great startup founders form real personal relationships with journalists. This isn't easy to do, but if you actually become friendly with writers they are much more likely to at least consider posting about your company. Good luck!
There are many consultants who can do this, but startups need to be realistic about what is newsworthy and what is not. A launch? If it's a great, innovative product, yes. A VC raise? If it's a notable amount of funding or the investors are well-known. A partnership? Rarely.
A great firm or consultant needs to be able to manage expectations with the client rather than promise constant press -- the latter is a red flag. In addition, the founders need to be willing to put in a lot of work as well. The startup is their story, not the consultant's, and the founders will be the ones who need to get out there and meet reporters. In the earliest stages, a PR consultant should be primarily a behind-the-scenes strategist (on messaging and branding) and a conduit for introductions to reporters. It needs to be the founders putting in the face time.
If you are a cash-strapped startup, my recommendation is to bring on a consultant to get press specifically for your launch or Series A raise. Having a firm on retainer can get expensive!
I'm happy to take a call if you want to discuss your options further.