A social wall does not necessarily mean social networks. Only one French person in 30 has a Twitter account and only one in two twittos has tweeted. It would be thus a shame to limit an interactive projection that is intended to be open to all.
Limitations of social networks
The number of Instagram accounts in France is similar to that of Twitter, if you limit your plan to these two social networks, you will reach just 5% of the French population. Even if you have envisioned inviting a very connected public (journalists, business leaders), chances are high that you will reach only 30% for various reasons: business mobile phones without applications nor private accounts, people visiting from abroad who do not have a data plan, etc...
High participation by text
A participation multiplied by 5 is noted when SMS reception is accepted. There are two main reasons for this. SMSs reach everyone with a mobile telephone (no need for smartphones, nor an account on social networks). But also because Twitter and Instagram posts are public. It is impossible to let go, send private jokes or photos at the risk of seeing them appear on one's wall. Messages out of context completely lose their meaning. Participation on social networks is thus much lower and more limited, more neutral and less funny.
An interactive projection is a fun tool, which should animate your event and make a lasting impression on your guests. SMSs remove the barriers to participation and engage the public more significantly. Remember that the rate of participation will ensure the success of your animation.
Presence on the Web
Social networks are often given preference by agencies, because the echo of an event on the Web is more easily quantifiable (number of occurrences of a hashtag, number of retweets, number of followers, etc.). Yet, Web presence through SMSs is significantly largely. Participants take a photo message in 50% of cases and share it with their friends privately by SMS, or via their Facebook walls.