Nationwide is doing also £500/£1000 cashback for saving up for deposit PLUS another £500 cashback if you are first time buyer + You can couple this with the help to buy ISA that gives you up to £3000 extra when you save up to £12000 ( £200 every month)

True but the key thing is you're restricted to YB's mortgages which could be poor

A "Help To Buy ISA" would give you a far greater bonus / "cashback" than this (up to £3k) and you have the flexibility of choosing a mortgage from any provider.

Agreed, especially compared to a deal a commenter posted about that's a full percentage point cheaper and 500 notes cashback, so essentially this one equates to an extra 750 quid in the short term for 1% more interest on twenty years of borrowing. Long term borrowing like this needs to be viewed over its entire lifespan.

Put it another way, go ask someone who has a mortgage if they would pay 750 quid to knock their mortgage rate down by a whole percentage point. I bet they would bite your arm off.

Haven't done the maths, but I strongly suspect the cashback would quickly be swallowed up by the extra interest

Be careful to do the maths and compare with other providers.

For example, if you borrowed £159,000 on a £200,000 house as a first time buyer with Nationwide they would give you a Flexclusive 2 year tracker rate of 2.29% with no fees, unlimited overpayments and £500 cash back.

​Yes but for a total of £1250 cashback with no fees; I think 3.29% is not bad at all!

I'd be surprised if you can find a first time buyers mortgage under 2%! Good deal if u ask me

Various recent marketing strategies to provide similar headline:
http://www.telegraph.co.uk/finance/personalfinance/borrowing/mortgages/10721252/Lloyds-adds-1000-cashback-to-its-95pc-Help-to-Buy-mortgages.html
http://www.propertyreporter.co.uk/property/halifax-offers-ftbs-1000-cashback.html
and others.
If you trust YB you can watch its TV advert for £1000 incentive: https://www.ybonline.co.uk/media/tv-advert/mortgage otherwise https://www.youtube.com/watch?v=ENrvl8KANfQ
2015 press release including "...both First Time Buyers and those moving home...":
http://www.ybonline.co.uk/media/news-releases/2015/new-mortgage-rates-and-cashback-210415

Good offer for those who have got this type of account, however it is no longer available to open as been replaced by the help to buy isa.

Good deal but only if YB mortgage deal rates are good.

Yes which is what I did and they gave me an extra £250 with no fees at 3.29% so I was happy overall

You only get the cash back if you take out their own first time buyers mortgage it says!!