Songs that had a huge week one sale and then dropped out of the chart pretty quickly. A recent example I can think of is Band Aid 30 which sold 313k in the first week and was out of the charts within two months.

Chartwise (nor culturally) songs like German Whip, That's Not Me, Shutdown and WickedSkengMan4 are guilty of this.

A lot of charity singles are guilty of having massive sales for a week or two, and then tumbling down the chart pretty quickly. Same goes for most of McFly's hits (to a lesser extent).

Zayn Pillowtalk this year had a big first week but couldn't sustain those sales like One Dance and Cold Water did

Songs like One Direction's One Thing and 5SOS' Amnesia had massive peaks in their 'release' week before dropping back 20 places! Not a massive fan of these type of songs tbh!

So many indie albums suit this. Radiohead and Muse spring to mind,

Anything and everything by Union J

Bionic by Christina Aguilera. Debuted at number 1 and then almost out of the top 30 the following week

Most songs that were released in mid-late 2015