The obvious question: is it safe to use a credit card online?

The simple answer: it's as safe as using your credit card anywhere else.... but there are some points to consider -

How big is the business you're dealing with?
- and how important is online trading to them?

- if this this is a big company that does a lot of business online then security will be very important for them, and they will have the money to fix it properly. The damage to their reputation if you lose money through fraud would be serious, so they will put huge amounts of their time and money into avoiding it.

- small businesses can't do that, so the good ones use third party payment systems, such as Worldpay (owned by the Royal Bank of Scotland, the largest in Europe) or Paypal (owned by Ebay, which is vast). Paypal claims over 100 million accounts - Maesbury Broadplace has one.
The small business website should transfer you to one of these for payment to be collected, they get their money back later from worldpay or paypal.
Look for the Worldpay or Paypal (or other third party) logo - but double check that you really are being taken to their website....

- if you are dealing with a small company that appears to be running its own payment system then you need to think very carefully about whether they can afford proper security on their own. Look for an explanation about security.

- if any website invites you to enter your credit card details without very clearly taking you to a secure server first, then do NOT use it! The padlock is the standard security logo.