Brian over at MicroISV speculates:
Now that Google is opening up the AdWords API, my guess is that we’re going to see dozens if not hundreds of apps that will handle scheduling of ads. By scheduling ads to appear at times when people are more likely to download my software, I have a better chance of both increasing sales and quite possibly, decreasing expenses. My other option is to use the API to increase the bids on my AdWords so that they appear first in the list during non-peak times which has the potential to increase sales during times that are traditionally slow.
My view is that it will take a while these apps to show up. Here's why I think the AdWords API adoption is going to be somewhat slow:
What could Google do to increase the adoption beyond the AmazEbayShoppingTag.coms? A few things are obvious:
Note that I don't think the choice of SOAP is a limiting factor. There are some who clamor for a REST version, but I think the AdWords API is more complex than most of the current REST things, and a different interface wouldn't spur adoption any faster. The AdWords API is a great thing because it's an early example of web services for the masses. Google should make it happen faster, though.