We sell a business product that includes website templates for the purchaser to use for their own business. Currently we include no link to our own website in these templates, as such a link (if visible) would not be in keeping with the customer's business. However I feel we are missing a massive opportunity to create numerous links back to our site.

Our website designers have suggested using a hidden link around a <br> tag somewhere in the templates index page. However I have read that there is a risk of SE's penalising for this. We rely heavily on Google Adwords for marketing and cannot risk problems with that account. We also show fairly well in Google's generic results for our major keywords, and do not wish to spoil this, but enhance it.

Such a hidden link as described above would not be intended to deceive the SE's, but simply to avoid spoiling the customer's website. The customer would not object to its presence.

Any comments/suggestions on the pros or cons of utilising this option?