As a user of a Search Engine, such as Google (the 800 pound gorilla), you want to be shown a list of pages which most closely meet your search criteria and are thus most useful to you. It is therefore in Google's interest to weed out all pages which appear to be "gaming the system" and trying to attract viewers through less than honest means. Such pages give low satisfaction because they are often not meeting the needs of users, but have entrapped them into a visit. It is a constant war between the search engines and those who manipulate the system to attract eyeballs, and techniques have changed over the years.
Some of these techniques are "honest", in the sense that they legitimately help search engines connect visitors to pages they want to see, while others are sticky tarbabies that merely trap visitors. Google is right to constantly change the rules to encourage honesty. Things like using proper markup (CSS instead of table layout, headings, alt and title tags, etc.) and placing keywords in content near the beginning of the page help a search engine to determine what's of value and should be indexed. Certain "off page" actions, such as legitimate backlinks from authoritative pages, can help. Almost everything else is manipulation of search engine algorithms and may not survive the next Google update.
I personally don't see any point in putting much effort and expense into presenting a manipulated page (and off page links) that could seriously drop in rankings tomorrow with an algorithm change. Just honestly present your case, make sure you have the keywords users might search for, do the things in layout and structure which make it easy for a search engine to find and rank keywords, and do reasonable "advertising" for your page with selective use of backlinks. Such actions should not suffer a big ranking hit in the next update, and you can spend your efforts on more useful things (like making a sale once someone gets to your page).