CIRP is out today with new data on carrier activations and growth for Q1. Unsurprisingly, Verizon and AT&T took the top two spots for the most activations, but T-Mobile did gain more new customers than any other provider. Additionally, the report gives more details on why T-Mobile and Sprint have fired up merger discussions again.

For CIRP’s 2018 Q1 results, Verizon came in with 28% of US mobile phone activations, followed by AT&T in second place with 23% (down from 26% YoY).

T-Mobile came in slightly behind with 21% of activations, while Sprint trailed coming in at 16%. “Other” carriers took the remaining 12%.

At this point, the four major carriers are more or less just swapping customers between each other. CIRP notes that Sprint lost 24% of its existing customer during Q1, but gained the same amount from other carriers. AT&T and Verizon also saw just a 1% increase in customers after gains/losses. T-Mobile saw the most growth with an 8% jump.

CIRP co-founder, Josh Lowitz, explains why T-Mobile and Sprint don’t have much choice to gain more marketshare besides looking at a merger again.