Is it correct to put a colon (:) before a website address?

[Hodge]

For example, "...create awareness and a fan base for the product using social media. Start by getting likes for the product's fan page: https://www.facebook.com/example"

You can see that just before giving the website I added a colon; is this a correct use of punctuation?

[David]

Yes, a colon is appropriate in this instance.

See:
The most common use of the colon is to inform the reader that what follows the colon proves, explains, defines, describes, or lists elements of what preceded it.
http://en.wikipedia.org/wiki/Colon_%28punctuation%29