Chapter 7's discussion of significance made some good points about making sites relevant and successful. I really enjoyed thinking about the aspect of exclusivity in online communities. Howard's example of the Obama website provided good evidence for the positive effect from exclusivity, but prior to reading that, I originally had a negative perception of these sites. From my personal experience, sites that debut as "invitation only" or anything like that can either by wildly successful and draw lots of attention, or they basically flop. I think the key to ensuring the former is making sure that the network isn't too exclusive. For example, Pinterest is quasi-invitation only, but just in the sense that you need to provide an email address for them to send you your "invitation". It's not actually that difficult to become a member, but that aspect of exclusivity, along with the generally popular concept of the site, is what contributed to its success, I think. However, I remember when Google+ first appeared it was strictly invitation only where a member would have to personally invite you to join the community. Because the idea of Google+ was so new and unique, not being able to visit the site and immediately explore and understand what it is, the exclusivity turned a lot of people away that I know of, including me.
Of course, Google+ is now very successful and I don't think the exclusivity actually turned away any significant number of people; they had the advantage of the Google name, which almost guaranteed their success alone. However, I do know that that element of exclusivity was an obstacle that may not be the best idea for brand new sites who don't already have users chomping at the bit for an invitation.

Heath and Heath's notion of keeping things simple seems really relevant today because of how dynamic and constantly changing modern technology and trends are. The desire to communicate and relate to people at its very "core" has been around for hundreds of years, but because of technology that idea has been able to manifest in a million different ways via online communities and social networks. You can notice that social networking sites, particularly the most successful ones, all carry with them the basic objective of communication, whether it be staying in touch with old friends, making new ones, discussing mutual topics of interest, etc. And there actually may be a lot of sites who share that core idea, but whose platform or means to facilitate that objective don't fit aesthetically or functionally with the user, and that could be an explanation for a lot of site failures. They have the best intention or goal, but perhaps they didn't fulfill that basic idea in the simplest way or they tried to plan too far ahead and in too complicated a way, to the point that their plan wasn't sustainable in the changing modern settings.
I also enjoyed the chapter, "Unexpected", which talks about the difficulty in getting and maintaining someone's attention. The Apple company comes to mind with the interpretation that sticky ideas are unexpected ideas. One of Apple's design and development objectives is to create a product with features that the consumer didn't even know they wanted, but that make perfect sense once they have them — these features are unexpected. And although Heath and Heath point out that "planned unexpectedness" is an oxymoron, I think this is a perfect example.

I really enjoyed what Howard had to say about symbols and codes in Chapter  6: Belonging. Symbols are one of the main ways in which humans communicate, so it makes perfect sense that a successful social networking community would implement a logo or inventive visuals in strategic ways to maintain users. Howard's example of the Clemson wordmark is a perfect example, because we all know the strength and emotion that image evokes. In an internet context, I immediately think of the two most popular social networking sites today and their logos (Twitter and Facebook). Everyone, whether they are members of those communities or not, instantly recognize the lowercase blue "f" as a representation of Facebook, or the little blue bird as a symbol of Twitter. This recognition is important for the marketing aspect of these sites, but it's also crucial to the sense of belonging that exists on these sites. When members spot these logos, they're both reminded to visit the site and also appreciative of their unique role in the success of the community. I think these images really have the power to make the users recognize that they are apart of this grander thing happening that has real value beyond their participation, but also that their participation contributes to this grander idea.