Possible reasons for being disallowed by Google AdWords:
1. Information harvesting
AdWords will disallow websites whose primary purpose is to capture personal information. The key words here are primary purpose. Do you have a legitimate website? Or is your entire website about capturing information? The former is great; the latter will get you into trouble.
As an example, a single page website whose only purpose is to capture personal information will likely be disallowed by Google.
However, a landing page with a lead capture form on the same domain as a full, transparent website with lots of information about you and how to contact you is a-okay.
2. Free gifts
Websites whose primary purpose is to offer free gifts or other incentives in exchange for personal information aren't allowed by Google.
3. No SSL for sensitive information
If you're looking to collect personally identifiable sensitive information such as credit card numbers, bank account numbers, wire transfer numbers or national identity numbers (such as drivers licence, social security / social insurance, etc), you need to collect this on SSL. In this case, contact the Instapage support team to discuss implementing a custom SSL solution. If you're looking to link from Instapage to a payment gateway to collect payment information, this can easily be done. Here's an example with PayPal.
4. Destination URL match
If the website that you're advertising is using the domain "abc.com," then your ad's display URL must also contain "abc.com." Google will automatically disallow an ad whose display URL and destination URL are on different domains. At Instapage, we recommend you use a custom subdomain for your landing page URLs.
For example, if your display URL is 'www.mysite.com' your destination URL could be something like "visit.mysite.com".
6. Use of re-directs
Don't try to get around step 4 with redirects! Google knows...
7. Nothing at the root of your domain/subdomain
When you set up your domain (or subdomain) with Instapage, make sure you have a page present at the root of your domain/subdomain. You might have any number of pages with paths like "abc.com/promo" but it's important to have a page at "abc.com" so to stay on Google's good side.
Good and simple practices for being approved by Google
White hat is where it's at! Don't spam and don't create a business based on information harvesting.
Use your own domain with your landing pages.