After reading this informative article you'll discover the good and bad places to get links.
Let's get the bad stuff from the way first. Link brokerage buy backlinks is generally bad. There are many reasons. To start with Google can simply detect those back links using reverse engineering and penalize your rankings. Second of, they often link out to spammers and don't produce great results with regards to rankings.
Now let's examine the good places to get links.
1) Paid directories: Spammers prefer quantity over quality. Payment often serves as a highly effective barrier to entry. Which means that a spammer will attempt to place links on 1000 ineffective directories and avoid investing in the high-quality directories. Virtually all paid directories have staff that reviews submissions. Search engines like sites reviewed by humans and let them have more trust. Most expensive directories are dir.Yahoo.com and business.com.
This is a set of secondary directories that it's worth submitting to:
You should review them manually, because unfortunately some of them change for the worst. At the time of this writing they're still good. Also Check your neighborhood directories (especially effective for local brick-and-mortar businesses)
This is exactly what you need to check: Do they accept all listings automatically once you spend them? If that's the case it's not really a good sign because spammers may buy links also. Just how many backlinks does the directory have? How often does it get crawled by Google (check info.directorydomain.com to see last cached date)? What is their Alexa rankings (how much traffic do they get)?
You can exchange links with directories, but only when they're vertical directories highly relevant to your industry. A great approach is to make a directory yourself and populate it with listings. Use it to url to directories which demand a link back in trade for a free listing. Never link back once again to poor directories.
Carefully examine the "directory submission services", often times they own most of the directories to which they're submitting. This can create poor backlinks for often astronomical prices.
2) Donations: Many non-profit organizations have a listing of individuals who made a donation. You can often make a small donation and get yourself a link back once again to your site. Several places have common keywords on site such as for instance "nfp", "npo" etc. Try searching for these keywords to find these organizations.
You will be doing something good while getting links in the process.