The First Ever Radio Ad

What was the very first radio commercial ever broadcast?
Here is your link to hear the ad broadcast on LBC:

https://audioboom.com/posts/487762-bird-s-eye-the-first-ad?playlist_direction=forward

Following this momentous occasion many more commercial stations were licensed in the UK, here is a timeline:
1973
8 October – LBC
16 October – Capital Radio
31 December – Radio Clyde,
1974
19 February – BRMB
2 April – Piccadilly Radio
15 July – Metro Radio
30 September – Swansea Sound,
1 October – Radio Hallam
21 October – Radio City
1975
22 January – Radio Forth
8 February – Radio City
19 May – Plymouth Sound
24 June – Radio Tees
3 July – Radio Trent
16 September – Pennine Radio
14 October – Radio Victory
28 October – Radio Orwell
1976
8 March – Radio 210
16 March – Independent Local Radio
12 April – Beacon Radio,