"Only rich companies can do PR because it's a luxury." What an absolute load of nonsense. The best form of advertising is word of mouth, always has been and always will. That's why, given a choice, you would much rather have an article in the Daily Mail telling everyone how amazing your new Doo Dah is rather than having to put your hand in your pocket and shell out £20K+ for an advert. It's pretty obvious which of the two will work better for you.
But we do understand why you are nervous about PR and your gut instinct is good. There are PR agencies out there who will take a thousand pounds a month off you, write three measly articles and then send you a list of the people they sent the article to - no guarantees. In our opinion this is bad practice that demonstrates no accountability. Using PR to your benefit is about creating the news first, then telling people about it. Good PR is about sending newsletters to your customers (with offers), it is about feeling confident you can ring the paper with a story, it's about having a story that's so interesting it's gets picked up by Google News or zapped around Facebook and Twitter.
Today, PR is about social networking, in other words, chatting with your customers where they hang out. We do this very well indeed.