In particular, the Google web spam team is currently waging a PR war on sites that rely on unnatural links and other ‘manipulative’ tactics (and handing out severe penalties if it detects them). And that’s on top of many algorithms already designed to look for other manipulative tactics (like keyword stuffing or boilerplate spun text across pages).

QUOTE: “If you want to stop spam, the most straight forward way to do it is to deny people money because they care about the money and that should be their end goal. But if you really want to stop spam, it is a little bit mean, but what you want to do, is sort of break their spirits. There are lots of Google algorithms specifically designed to frustrate spammers. Some of the things we do is give people a hint their site will drop and then a week or two later, their site actually does drop. So they get a little bit more frustrated. So hopefully, and we’ve seen this happen, people step away from the dark side and say, you know what, that was so much pain and anguish and frustration, let’s just stay on the high road from now on.” Matt Cutts, Google 2013
Ideally, you will have unique pages, with unique page titles and unique page meta descriptions . Google does not seem to use the meta description when ranking your page for specific keyword searches if not relevant and unless you are careful if you might end up just giving spammers free original text for their site and not yours once they scrape your descriptions and put the text in main content on their site. I don’t worry about meta keywords these days as Google and Bing say they either ignore them or use them as spam signals.
The basics of GOOD SEO hasn’t changed for years – though effectiveness of particular elements has certainly narrowed or changed in type of usefulness – you should still be focusing on building a simple site using VERY simple SEO best practices – don’t sweat the small stuff, while all-the-time paying attention to the important stuff  – add plenty of unique PAGE TITLES and plenty of new ORIGINAL CONTENT. Understand how Google SEES your website. CRAWL it, like Google does, with (for example) Screaming Frog SEO spider, and fix malformed links or things that result in server errors (500), broken links (400+) and unnecessary redirects (300+). Each page you want in Google should serve a 200 OK header message.
If you take money online, in any way, you NEED to have an accessible and satisfying ‘customer service’ type page. Google says, “Contact information and customer service information are extremely important for websites that handle money, such as stores, banks, credit card companies, etc. Users need a way to ask questions or get help when a problem occurs. For shopping websites, we’ll ask you to do some special checks. Look for contact information—including the store’s policies on payment, exchanges, and returns. “ Google urges quality raters to be a ‘detective’ in finding this information about you – so it must be important to them.
Another excellent guide is Google’s “Search Engine Optimization Starter Guide.” This is a free PDF download that covers basic tips that Google provides to its own employees on how to get listed. You’ll find it here. Also well worth checking out is Moz’s “Beginner’s Guide To SEO,” which you’ll find here, and the SEO Success Pyramid from Small Business Search Marketing.