Give and you shall receive. The beauty of reciprocity is the mutual respect or action taken toward another individual or in our case business.
Now the mom blogger's of the world have this step down pat. But we need to understand the steps and importance to being reciprocal and how to do it effectively.
Some businesses out there would say, "I'd rather pay a large site with more traffic to put my ad on", or "I want someone to pay me to put their advertising on my site or in my comments".
Here is the deal, yes you can make money by others advertising on your site, but two paid ads with blank or "advertise here" space won't give your site the credibility that 7 free ads will. With your site advertising for 7 others, it makes your website look more read, more visited, therefore more credible, transversely, 2 ads may have made you $50 for the month but made the site look new, not desirable, or lower traffic. And, although posting other blogs that you read is fun and sweet, I would only post the ads for blogs that tie in a business or service, again a credibility issue. Don't get me wrong there are a lot of good blogs out there, but in the business world, the perceived success is how much money you are bringing in from advertising, products, etc.
You may need to try this step for a few months to make sure people are seeing and believing your presence online.
Obviously once you are contacted for advertising that pays, then you send a thank you note to those free ads that will be replaced for paying ads and maybe make a mention of how much you like the products/blogs from the free advertisers in a post or two.
REMEMBER, there is no reason, other than the other advertisers themselves, that the public needs to know those ads are free. In addition you should have an ad rate card ready from the beginning so you are prepared when you receive these requests.
It is all about the give and take, with the nagging reminder of perception. Do another business a favor, they will almost always return it.
Other ways to reciprocate other than advertising space, is mention of other businesses in posts, comments, thank you's, etc. Or, try a partnership for a giveaway. I am not talking about a $10 cooler, but with two or three of you partnering, you can afford a more comprehensive giveaway. Even if it is a compilation of all the partners products tied up with a bow. The way to make that work would be that all three partners would advertise the giveaway with a tile ad, a few posts and links to the other partners. Work together. There is no reason to go it alone, especially if you are a new site, that does not matter, if your information is smart and actionable, you will start to see the response.
Business is all about working the outlets you have available, and reciprocity is usually a free or low cost way to build visibility, confidence and credibility. If someone turns you down, go onto the next. Don' waste your time on those that have the huge numbers, focus on those that will appreciate and return your business, because they see the value in the partnership too.