A couple of comments:
1) From my experience managing large AdWords campaigns for 2+ yrs, I’d say that “day-parting” or choosing when to run ads in order to reduce cost is not the right thing to optimize unless you are spending upwards of 20k/month on AdWords. Day parting may make sense for high volume sellers who have very good understanding of their demographics. If you have already focused on:

- Keyword selection
- Ad Copy optimization
- Landing page testing and design
- Store usability
- Customer satisfaction.

Then day parting and other bid management strategies are worth exploring. In other words, there are better ways to spend your time if you are looking to maximize profit on an AdWords campaign. Consistently focusing on keywords, ads and landing pages can easily increase conversion rates by factors of 2x or 3x.

2) For more comment on the AdWords API, and why I think it’s not being adopted as fast as it could be, see http://gotads.blogspot.com

1) I’ve worked with AdWords for over 2 years, managing several large accounts. As a Micro-ISV, you do not want to overthink your approach. Choosing “peak times” for ads (aka dayparting) is usually not an optimization that you need to worry about unless you’re spending $20K a month or more. More important things to worry about first:
- Keywords you buy.
- Ad Copy - what your ads say
- Landing pages - what the page the visitor first sees after click your ad
- Your shopping cart ease of use.
- Your customer support.

My experience is that “day-parting” is akin to day-trading. For a Micro-ISV, it’s really not the best use of time. Do not optimize the wrong thing… Take that energy and focus on more keywords, or better copy or testing your landing pages. That will pay off with 3-5% increases in conversion rate.

2) Your post on the AdWords API inspired some comments over at my http://gotads.blogspot.com blog where I talk about PPC ads regularly.

As for #2, I’ll take increased sales any time I can get them, provided it is in the best interest of my business as a whole. My goal is to get more people to purchase who may be on the fence. Like everyone, especially if an incentive decreases my profit in any way, I’d like for the people willing to pay full price to pay full price and for those who are on the fence to be paid customers as well, as long as I can do so without making it a losing proposition for me. The other option I would prefer is to have people pay more quickly.

The statistics tell me that there could be more room for growth on the non-peak days, so that’s where I would start. Most shareware developers would be very happy with a .5% or 1% increase in their conversion ratio, especially on traditionally low sales days. There is more room for growth on the days that are not currently the highest in terms of purchases so why not start there.

1) Make ads more visible during non-peak times
2) Offer incentives to purchase on non-peak days

Assuming the ads cost money, why would you want to (presumably) pay more in order to make them more visible during a time when people are less receptive to buying? If it is to increase the sales, then shouldn’t you also want to increase the sales during peak times as well?

If you have incentives to purchase on non-peak days, why not offer those same incentives on peak days to further increase sales (make the peak even higher)?

Just curious