If you take a look around the Internet and visit a few websites for local companies, you are likely to find a link at the bottom of every page to the company who designed that website.
That may seem a lovely idea, a nice way to promote the web design company who created your website, which is true - in fact once this year I have been asked to specifically add such a link for one client who was really pleased with the work I'd done. However, I turned down the offer and gave my reasons why.
I openly admit, many of my early website designs did have a back-link in the footer to Light Bulb Web Design, at the time I felt it was appropriate advertising and was somehow going to make sure I gained more clients from those who visited the websites I'd created, saw my company in the footer and chose to get in touch. However, in reality, none of the enquiries I've had in over 4 years have ever mentioned seeing my company listed in this way as the reason why they called. Referrals have always been through word of mouth, from my client's customers asking them who did their website and being recommended that way, or though other local businesses I know through networking and similar groups.
That in itself is not the main reason for my decision to stop doing this though - the bottom line, for me, is that any website I design is for you and your business, not my own. You don't visit Amazon and see 'Designed by Light Bulb Web Design' (I wish!) in the footer...
The initial idea of no longer doing this came from the only client who ever asked me to remove the link I added during the design process. They even used the word 'process' in their reasoning as to why - specifically, they did not want to show process on their website, they wanted the site to stand alone as their own brand and not show any evidence of how it got there.
That made me think and whilst initially I was a little unsure of changing, when you consider that aside from buying branded goods with logo's on, where as with website footer links, you are paying that supplier, that brand, to provide you with a product but also to advertise for them...
Nobody buys a house and lets the builder put a big sign up saying 'Built by...' so why should your company website be any different?
From the other perspective, it may seem that such links are good for my own search engine optimisation, however the exact opposite can be true - leaving these links in as ones which search engines are allowed to follow can, under Google's own guidelines be considered a Link Scheme - a way to increase back links to a given website and manipulate search results. If Google sees this for your website design company, it can have a negative impact on your rankings for something which initially seems like it will actually improve your reputation.
I did personally expect to see a drop in my own site rankings as I stopped adding these links for clients, but it has had no impact what so ever, certainly my own rankings in local results are as strong as ever.
There's also the potential for a minor negative affect for your client's websites too...so why risk your own reputation and their own for something which in my experience, has made no difference to how many enquiries I get, nor on my own website search ranking results!
Your website is your own, and we have no desire to shout about our own business on it :)