For many affiliates, their worst business decisions involve merchants. Choose the right one, and you’re part of a win-win scenario that can last for years to come. But choose the wrong merchant, and you may find yourself out-of-pocket with no zero on your ad spend.

So checking merchant repuation should be done early on, as soon as you find a promising offer. Here are some tested tactics that will help you check out the current reputation of merchants and networks.

Tip #1 – Don’t rely on the merchant’s press. While press releases or corporate public relations copy can be helpful, remember that neither is an accurate assessment of the quality of a merchant. Read a press release not as “news,” but as soft-pedal marketing. (Note: Once you sign up for a program, be sure to sign up for Google Alerts about that merchant. You’ll get notifications of press releases and other news items, sich as new product anouncements.)

Tip #2 – Query the search engines. Go to your favorite search engine and query the merchant’s name plus words like “commission problems,” “payment issues,” and so on. Do some serious digging down through several pages. You can do the same with affiliate networks. While you’re there, do an additional search for the merchan’ts name plus “affiliate manager” and “contact.” That information will come in handy later.

Tip #3 – Check trusted blogs and forums. The web’s informal network of forums, blogs, and marketing sites will often give you a good feel for the ethics of a merchant. Look for posts about the merchant on affiliate marketing forums like 5 Star Affiliate Programs, as well as blogs known for objectivity (the 5 Star Affiliate Programs Blog is a standout here as well).

Tip #4 – Do basic due diligence. How? The way you would check out any other company. Study their support page. Do they have phone and email support? Do they have a trouble ticket system? Networks and merchants with proactive management will always be easier to work with, especially if you have a dispute over commissions or referrals.

Tip #5 – Does the merchant have a dedicated affiliate program manager? Dealing with a real person – not an automated system – can make all the difference. An affiliate program manager often has the authority to investigate and report on matters with a simple phone call or email. Programs like this are worth promoting!

As affiliates, we all know the biggest problem with cookies isn’t that they expire. It’s that they can be overwritten, erased, purged, or otherwise “messed with.” So every affiliate should know about these tips for checking and testing cookies.

Use cookie length as a tie-breaker. When deciding between merchants with very similar conversions, commissions, and EPCs, go with the merchant that offers the longest cookie length. This is especially important if you’re paying for traffic. Many visitors won’t make a purchase on the first visit, and a longer cookie increases your chances of getting credit for the sale if they visit the merchant site later.

Check to see if the cookie “expiration” date is correct. Click on one of your own affiliate links. Then find your browser cache folder and open it. Look for a file with a name similar to one of these:

cookie:yourcomputername@merchanturlname.com/
cookie:yourcomputername@www.merchanturl.com/

The code should contain an expiration date, so check it see if it’s the same length as the cookie the merchant claims to set. If the cookie length isn’t there, or if it’s inaccurate, contact the merchant. Don’t accuse — just politely ask about the cookie length and send them a copy of the cookie code (a screenshot is best). Most of the time you’ll get a grateful reply and a promise to follow up.

Don’t take cookie length for granted. How can you be sure that a merchant’s “90 day cookie” really lasts for 90 days? The only absolutely reliable method is to have someone click your affiliate link and make a test purchase shortly before the end of the cookie’s lifespan. (Of course, be sure they’re not blocking cookies or nuking them with anti-spyware software.) Have them document the purchase — print receipts and take screenshots, noting the time and date of the sale. When you log into your affiliate account, you should be able to see some evidence of the purchase.

Yes, this is a lot of trouble, but if you suspect problems with the merchant’s tracking mechanisms, it’s the best way to test them out. If the purchase doesn’t track, be sure you contact the affiliate manager, and send an explanation of why the purchase was made with copies of all documentation.

Understand that merchants can’t control some cookie problems. If a consumer is using a browser that blocks cookies, that’s not the merchant’s fault. Parasiteware affiliates can and do hijack cookies, though merchants and networks are getting better at weeding out these black hats. And sometimes the merchant cimply doesn’t realize that their tracking mechanisms have malfunctioned and aren’t setting cookies correctly.

Use snail mail, phone, or fax when contacting a merchant. Remember that today’s spam filters could be trashing your emails before the merchant can see them. So when contacting a merchant about a malfunctioning cookie, look for a phone number, a snail mail address, or a fax number — and use them. If after repeated tries you get no response, check the cookie one more time. If it’s still not working right, you’re better off trying to find another merchant.