What does the Indexer Extra do?

There are 3 levels of indexer service:-

• The indexer #1 is a complex process that ensures that all of the backlinks have been crawled by Google spiders, it is including some techniques such as shorten your links, ping each single link, create RSS feeds, create XML sitemaps... etc.
• The indexer #2 will include all processes in the indexer #1 more than 1 time + some extra tactics to get high indexer rate not only crawled by Google.
• The indexer #3 have all processes in the indexer #2 plus submitting each backlink to 1k - 2k of authority filter sites like whois, redirect, stats... etc.

*The indexer #3 gives the maximum indexer rate