Evaluate First Before You Join an Affiliate Program

Some important factors to consider are:
Products
Every affiliate program should have some products to sell. These products may be physical products that require delivery or e-products that require instant downloads after online payment. A good affiliate program should have some products that can be selected by the affiliates to offer to the market. The programs which only have a few products need not to be considered for such programs can be considered not strong enough and can be collapsed any time due to financial crisis. Programs that have hundreds or even thousands of products usually are strong; volume is a sign of their strength. A good affiliate program should offer a product of different categories, so an affiliate does not feel the need to search for another affiliate programs if he wants to promote other kinds or types of products.
Organization's Track Record
Try to learn as much as possible the track record of the affiliate program you consider to join. It is not difficult to do this, you can use search engines for this purpose. Simply by typing the affiliate program's name that you are interested in and all the information available on the internet for this affiliate program will you get in front of you. Look also at the testimonials present at the program's website and find out about how long the program has been in business. Better to avoid new companies or new programs. Strong organizations always show their annual revenue generated, from this you can easily determine the success of the organization or program. Also find out comments or reviews of the merchants and affiliates that have joined the program. With the answers you get from the above questions, we can say you already get enough information about the affiliate program and can more easily determine which programs you should or should not join. 
Support Available to Affiliates
Many affiliates are new in the affiliate  marketing field, and they do not know much about this business, they need guidance and suggestions at every step. On the other hand, people who have experiences in affiliate programs and have run this business for years know a lot about the difficulties and solutions in this field. If you are an affiliate and want to join an affiliate program, look whether they are willing to provide good support for you in the business, because if you do not get proper support, then you may only will waste your time and money.
Payment
Check payment methods available and offered to the affiliates in each affiliate program. If they only offer payments in some special method, check whether you can use that method. For example, if a program pays  through Paypal, then you should see if you can receive payment via Paypal in your country, because Paypal is not available in every country.
Conclusion
Do not rush to join an affiliate program. Conduct research and collect accurate information about a program before you decide to join. The Important things to consider are their products offered, their payment schedule, their support and previous track record. You can get all this information through search engines and on the official site of the organization. If this organization has done business for years, has many products offered, giving good support to their affiliates, and  has good payment schedule and options, then you could join this organization. Avoid the organizations that are new in the business and do not have many products to promote, because that will only waste your time and energy.