So, a popular soap brand introduces a soap themed on a rivals in order to both protect its own market share (at a lower or higher cost), plus offer a different brand experience to the competitors. A Unilever has many soap and detergent brands at different price points and categories. Likewise for almost any brand. The best example is the automobile market where there are brands owned by different companies and it is quite difficult to figure where the ownership goes up to.
In India, AAP is the flanking brand for Congress.
The AAP is a masterstroke. It started off as India Against Corruption - a direct result of the great Indian corruption scheme launched under UPA1 and grown vigorously under UPA2. Soon, the original founder members parted ways leaving India Against Corruption with a few people. These few people got together to form what is known as the AAP.
The AAP made all the right noises. Peoples participation, neutral agenda, fight against corruption, crony capitalism, collusion - all the right words that get the voters goat. And translated the votes into a spectacular victory in Delhi State elections. At this point, they could have stayed genuinely neutral, but guess what they did - they allied with the Congress (against whom the entire anti- corruption was aimed at) - instead of allying with the BJP (for whatever reason). The ostensible story was that the BJP was communal while the Congress was saykoolar. Be that as it may, subsequent efforts by the AAP pointed that the AAP was primarily interested in protecting the Congress in the manner that they quietly started ignoring the CWG scam and so on and so forth.
Post the 49 day fiasco, AAP came back with yet another spectacular victory that gave them an absolute majority in the house. Yet, even after that (and a huge internal fight which Kejriwal won by unilaterally throwing out dissenters) the AAP refuses to do much on the much hyped anti-corruption platform. Indeed, that has almost been forgotten.
Now cut to the Bihar elections. Where the AAP has offered to support - hold your breath - Lalu Prasad Yadav who has been convicted in a massive Fodder scam. So, whither anti corruption?
Because if AAP fights on its own, it will eat into its main brand - the Congress - or what has now become a grand alliance against Narendra Modi - whose government is probably the cleanest since NDA 1 or perhaps Lal Bahadur Shastri before that.
So the AAP is now protecting the main brand of which it is a flanker (or perhaps it is the other way round). Ever notice, Kejriwal never, ever, ever, ever criticises Sonia Gandhi? Therein lies an answer...
PS: Ironically Yadav himself came up on a (again, hold your breath) anti corruption platform in the 70s. From the wiki entry on Yadav:
Yadav entered in student politics as General Secretary of the Patna University Students' Union (PUSU) in 1970 and became its president in 1973. In 1974, he joined Bihar Movement, a student movement led by Jai Prakash Narayan (JP) against rising prices, corruption and unemployment. PUSU formed Bihar Chhatra Sangharsh Samiti to spearhead the agitation with Lalu Prasad Yadav as its president.
So, perhaps Kejri is the Lalu of the 2010s as a twitter user wryly observed.