If you have an online presence, and your website is mundane without the initial instigating factor which drives and draws your target audience to want more from you; you'd have to dangle the carrots so to speak.
There are many marketing tools that are available online, and can be branded/private labelled for a fee. Directing your site visitors to another site usually allow for the retention factor to dissipate elsewhere.
Business is more than a game of Monopoly.Marketing, the other.
Having your own Wallpaper, Puzzle, or Trivial Pursuit Board Game is one way to incite the Instigating Factor to all your potential, and non-potential clients. Advertising is another.
Without having to spend a fortune on Internet Advertising, and/or Below The Line Offline Advertising to keep your online presence interesting enough for audience to want to return, is the Viral Factor that you would need to create, or re-engineer/re-think.