E-mail Marketing
This..and I think most would agree...is the best and most valuable marketing you can do.
Each visitor to your site has arrived because you offer something they want, something they need, something they are interested in or something they want to learn...so each visitor is hugely is valuable.
Capture their names and e-mail addresses so you can stay in touch and gain a customer for life.
In the law of averages most people don't buy anything on the first, second or third visit, they probably look at loads of sites and then decide whats best for them...
So if they don't click your links or buy from your site don't stress..they probably didn't buy anything anywhere...think of your habits...did you buy everything you were offered even if you wanted it?
It's crucial to have an opt-in subscription box on your site for people to start receiving a weekly or monthly newsletter. My personal favorite is SUMOME (free plugin) and Mailchimp (best free service)...but loads of others exist.
Email Marketing leads to sales....most people will open and read and click a link in an email MUCH MORE than clicking banners on your site