1. How to choose good keywords? Should I go for keywords with high competition or not? 2. How much should I bid? How much should be my daily budget? (for ZIP and Email submits) 3. Should I activate Content Network? 4. Does Promoting Referral Links directly, affects and lowers the Quality Score?
All of those answers and far more are available at the first link in my sig. It's a community of people that share their methods and success with adwords. There are also a ton of guides on things such as "Finding keywords", optimizing landing pages, Uses for the content network, how much to bid, direct linking and tons tons more. In short to answer your questions: 1. Lower Competition keywords are going to have a cheaper cpc. It all depends on if you can make an ROI with your product. 2. How much you should bid depends on the keywords you are using, same with daily budget. A good rule of thumb is to set your daily limit to what you would make for a sale. In this case, with email and zip submits you may want to do some testing with your campaign first and see what your conversion rate is, and then figure out how many clicks it takes to be profitable and adjust your limit accordingly. 3. The rule of thumb is to disable the content network in the beginning and then once you get the search network nailed down, experiment with content. 4. Direct Linking does not lower quality score it itself. The quality score is based off of the landing page quality and what you pay. If the landing page is highly relevant to your keywords and ad copy, the score will be higher. I have learned all of this and far more at Wealthy Affiliate. Check the top link in my sig to find out more.
Is the first part of the Wealthy Affiliate program to promote the shit out of it? You guys never miss an opportunity to plug it in, quite amazing.
High competition = High cost, but they cost a lot because they work, (usually). If you're doing zip and email submits, you should be looking for cheap clicks. If the zip pays $1.50 and you want 100% roi and assuming you're converting at 5%, you can bid $0.04 maximum per keyword. Absolutely, turn the search network right off for these type of offers. Usually it will, but there's a couple workarounds for this.
It depends on whether or not there are other affiliates bidding on the same keywords and if the merchant is also bidding on them. If so... bye bye direct linking. It also depends on whether or not the merchants page is optimized for your chosen keywords... if not, bye bye direct linking. Do yourself a favor and just build your own landing pages for your own sanity down the line!
Of cause, if they are relevant to your offer. Mainly you MUST track small ad groups or keywords: what you get after 20-50 clicks? Does it convert?