I have a robots.txt file in the root to prevent search engines indexing any of my sites. I have a social media management application embedded on my site that includes all major social media channels including G+. I heard that once the G+ symbol is on a site Google will index sites despite having a robots.txt in the root. Is this true? My thought behind locking out robots for a while is so I increase visitors per day first before allowing robots to crawl. Once I e.g. reach 100 visitors a day I will remove robots.txt file and will then receive a better initial page rank (in mind that PR is only updated every couple of months). Is this reasonable? How much emphasize is placed on the factor %visitor increase/day? 
Does Google crawl page when G+ logo is embedded?
seo;robots.txt;pagerank;social media