I had a company call me to tell me that my clients website was not effective because it did not have conversion tracking and remarketing tags installed on the website.

Watch out for these type of call because they are ill informed.
They follow the Google playbook to a tee and do not do any thinking for themselves.
These tools that Google provides are great when used appropriately.

Conversion Tracking

The purpose of conversion tracking is to collect data on check out pages or other metrics that you define. This is great for website that all or most conversions actually happen on the website. This data is then applied to your PPC campaigns to optimize your ads and help to increase sales. All sounds great right. For Our clients (Local Direct Sales through website and phone) we know that at least 50% (which is our target) of the conversions are through phone calls. This means that at a minimum the conversion tracking metrics that are used to optimize the campaign are at least 50% off! That is way to high or me to trust such an application to manage my clients budgets. Google now offers 800#'s that can be used to track calls on your website to address this deficiency (Jan 2015) Problem!!! 800# reduce website conversions for local businesses.

Remarketing Tag

This is an interesting tool that helps you to target visitors that have visited your website previously and present them with an ad to invite them back. Sound pretty cool right! It is, BUT, this only works on websites on the display network. The display network is a network of advertisers that use the adsense service on their website. This traffic tends to be of less quality and lower purchase intent then your direct source through search engine marketing.

Google Campaign Recommendations

We have spoken with many google campaign support specialists and implemented many of the recommendations that they provide. For the most part we find that the recommendations provided typically increase costs and do not increase volume, targeting or quality. I guess that makes sense for Google.
If you are seeing results on your campaigns that are solid then stay the course.

What is most important is that you see the ROI your are looking for over any recommendation.