WildCard SSL Certificates
A Wildcard SSL certificate will allow to protect a domain name and any sub domains under that domain name. This means that you can protect your domain and sub domains all with one certificate. It can be very much cheaper than buying a single certificate for each sub domain, in most cases. It will also makes things easier. This is because you just have to renew everything once a year in one go, rather than having to renew each of the certificates on the individual sub domains. It is therefore worth calculating which of the options will be the best for you.
A wildcard certificate will protect your root domain and sub domains which are under the hierarchy from that root domain. This does not just mean the second level either but all levels in the hierarchy. As long as they are under the same IP address they will get protection from it. It is important to your customers that they do get protection when using their website. You will be able to build up trust with them if they can see that the site is secure. Many will not consider doing anything online with regards to providing any personal details, especially financial ones, if they cannot see that the site is protected so that their data will be encrypted. You could lose a lot of customers if they do not believe that their personal data will be kept safe.
It is also important to note that Google uses SSL encryption as criteria when deciding how high to list you in search engine listings. This means that without it, your domain and sub domains may not show up on a Google search result. This could have a catastrophic effect on the amount of traffic coming to those sites and could mean that you will lose a significant amount of sales. Alternatively, if you are near to the top of the list, you will find that you could attract more traffic than before and your sales could rocket upwards