Promoting a website is expensive. Getting a site to receive traffic takes time, money or both. So it is important that the time and money we spend is spent on worthwhile promotions. This means checking each possible link buy or trade to be sure that it will have the desired affect on your site. To a large degree the criteria for a good link is the same whether you are looking to increase your PR, raise your site in the SERPs or gain traffic from the link.

If this is an expensive link you are likely to spend a great deal of time manually checking out the link, if it is a low cost link you will likely be able to use a simple tool like the one at Insane Stats to get the information you need. Either way you should start the process already having a good idea what you are looking for in the deal.

Here are a few of the main things I look for in a link buy or trade and why:

• PR - Yes, this still makes a difference. You want Google to know about your link right? Well, if the page has a decent PR, you have a pretty good idea that Google, and likely the rest of the search engines regularly visit the page.
• Cashe - Be sure the page is cashed, if it is not, there may be a problem with the page or the site.
• Alexa Rank - Doesn’t hurt. This can be easily manipulated, but it can still give some idea of the traffic to the site.
• Backlinks - Very important! But more than just the number should be looked at. It’s pretty easy to get hundreds or thousand of links to a site even if it is of low quality. Check some of the links, what types of sites are linking to the site you wish to get a link on? Spammy, Low Quality, Mostly Free Directories? If so, there is likely very little traffic going to the site. No Traffic means no referrals to your site, and low trust from the search engines.
  High quality, related links, likely mean that the search engines trust the site and it is getting traffic.
• Traffic Stats - Unfortunately this one means trusting the person that is trying to sell you a link! Often they are not the most reliable source of unbiased information. Remember that these stats can be faked in many ways. Not the least of which is to buy a ton of traffic right before you take the screen shot of the stats.

How much time you spend will often be determined by how much you are going to spend on the link. A $5.00 per month link might be worth just purchasing the link for a few months and seeing how much traffic and benefit you get from it. A $500 - $1000 annual link requires much more thought. You can buy a lot of adwords clicks for that much money, make sure you will really see an increased benefit before you buy!