Many online shops have the number 24 in them, to signify 24 hours a day – you may also be able to integrate numbers into your domain in a meaningful way to make them unique. Be careful though, because many cultures attach a lot of significance to certain numbers. Make sure that your number doesn't represent bad luck or other negative things in the country you're operating in.
Yes. We recommend buying not only your domain name with your favorite extension (eg. .com), but also additional, alternative domain extensions (eg. .net, .info, etc). The reason is simple. Having more than one domain extension strengthens your online identity, secures your brand name and improves your online presence. Buying more than one domain extension also protects you from your competitors registering your additional extensions and enticing away your customers.